MySQL Connector/C 6.1 provides these features not present in 6.0:

  * Support for the pluggable authentication framework that
    enables implementation of authentication methods as
    plugins. This framework can be used for MySQL native
    authentication as well as external authentication
    methods. See Pluggable Authentication
    (http://dev.mysql.com/doc/refman/5.6/en/pluggable-authentication.html).

  * Client-side support for the SHA-256, PAM, and Windows
    native authentication plugins. See The SHA-256

    Authentication Plugin
    (http://dev.mysql.com/doc/refman/5.6/en/sha256-authentication-plugin.html),

    The PAM Authentication Plugin
    (http://dev.mysql.com/doc/refman/5.6/en/pam-authentication-plugin.html),

    The Windows Native Authentication Plugin
    (http://dev.mysql.com/doc/refman/5.6/en/windows-authentication-plugin.html).

    The older MySQL Connector/C 6.0 can connect only to
    accounts that use native MySQL passwords. If a client
    program attempts to connect to an account that requires a
    different authentication method, an "Access denied for
    user" error occurs.

  * Support for connecting to accounts that have expired
    passwords. See Password Expiration and Sandbox Mode
    (http://dev.mysql.com/doc/refman/5.6/en/password-expiration.html).

  * Support for prepared CALL
    (http://dev.mysql.com/doc/refman/5.6/en/call.html)
    statements. This enables client programs to handle stored
    procedures that produce multiple result sets and to
    obtain the final value of OUT and INOUT procedure
    parameters. See C API Support for Prepared CALL
    Statements
    (http://dev.mysql.com/doc/refman/5.6/en/c-api-prepared-call-statements.html).

  * Support for connecting over IPv6. See IPv6 Support
    (http://dev.mysql.com/doc/refman/5.6/en/ipv6-support.html).

  * Support for binding client programs to a specific IP
    address at connect time. See mysql_options()
    (http://dev.mysql.com/doc/refman/5.6/en/mysql-options.html).

  * Support for specifying connection attributes to pass to
    the server at connect time. See mysql_options()
    (http://dev.mysql.com/doc/refman/5.6/en/mysql-options.html),
    and mysql_options4()
    (http://dev.mysql.com/doc/refman/5.6/en/mysql-options4.html).

Changes in MySQL Connector/ODBC 5.2.5 (Not released)

   Bugs Fixed

     * The query_print() function could cause a serious error on
       32-bit systems due to a 32-bit / 64-bit mismatch in its return
       value. This error could occur when logging was enabled, for
       example when using configuration settings such as:

        [Driver]
        option=524292

       (Bug #16367440, Bug #68201)

     * Microsoft Access could experience a severe error when updating
       a BIT column in view representing a MySQL table, for example
       through the datasheet interface. (Bug #16287859, Bug #68243)

     * Datetime and timestamp second fractions need removing the
       trailing zeros (Bug# 16294197/65418)

     * Binding string to decimal parameter always uses system locale
       setting (Bug# 11766369/59469)

     * Added CLEARTEXT authentication connection option
       ENABLE_CLEARTEXT_PLUGIN. (Bug#16445091)

     * Crash in SQLSetConnectAttr(SQL_ATTR_CURRENT_CATALOG)
       (Bug# 16526604/63844)

Built against the MySQL server 5.6.11 client library.

     * Replication: In certain cases, the dump thread could send a
       heartbeat out of synchronisation with format description
       events. One of the effects of this issue what that, after
       provisioning a new server from a backup data directory and
       setting --gtid-mode=ON and enabling autopositioning (see
       CHANGE MASTER TO Syntax
       (http://dev.mysql.com/doc/refman/5.7/en/change-master-to.html)
       ), replication failed to start, with the error Read invalid
       event from master.... The same problem could also cause
       GTID-based replication to fail due to skipped events following
       a unplanned shutdown of the master. (Bug #16051857)

     * Replication: In some cases, when the slave could not recognize
       the server version of the master, this could cause the slave
       to fail. (Bug #16056365)

     * Replication: Dropping a table that includes non-regular ASCII
       characters in the table name caused a replication failure. The
       parser converted the table name into standard charset
       characters and stored the table name in the table_name
       variable. When the drop table query was regenerated using the
       table_name variable, the table name was not converted back to
       the original charset.
       Additionally, table and database names with 64 characters
       caused an assert failure. The assert required the table or
       database name to be less than 128 characters. Latin characters
       require two-bytes each, which requires an assert condition of
       less than or equal to 128 bits.
       The fix includes a new function to convert tables names back
       to the original charset, and a correction to the assert
       condition allowing table and database names be less than or
       equal to 128 bits. (Bug #16066637)

     * Replication: When using GTID-based replication, and whenever a
       transaction was executed on the master but was not sent to the
       slave because the slave already had a transaction with that
       ID, semisynchrononous replication timed out. One case in which
       this could happen was during a failover operation where the
       new master started behind the new slave. (Bug #15985893)

     * Replication: An unnecessary flush to disk performed after
       every transaction when using FILE as the replication info
       repository type could degrade performance. Now this is done
       only when both data and relay log info is stored in
       (transactional) tables. (Bug #15980626)

     * Replication: When reading row log events from the binary log,
       the slave assumed that these events were always valid; because
       of this, an event having an invalid binary log offset could
       cause the slave to crash. Now in such cases, the slave fails
       gracefully, and an error is reported, if any of the fields in
       a given row event are invalid. (Bug #15829568)

     * Replication: Table IDs used in replication were defined as
       type ulong on the master and uint on the slave. In addition,
       the maximum value for table IDs in binary log events is 6
       bytes (281474976710655). This combination of factors led to
       the following issues:

          + Data could be lost on the slave when a table was assigned
            an ID greater than uint.

          + Table IDs greater than 281474976710655 were written to
            the binary log as 281474976710655.

          + This led to a stopped slave when the slave encountered
            two tables having the same table ID.
       To fix these problems, IDs are now defined by both master and
       slave as type ulonglong but constrained to a range of 0 to
       281474976710655, restarting from 0 when it exceeds this value.
       (Bug #14801955, Bug #67352)

     * Replication: MASTER_POS_WAIT() could hang or return -1 due to
       invalid updates by the slave SQL thread when transactions were
       skipped by the GTID protocol. (Bug #14737388)
       References: See also Bug #15927032.

     * Replication: Trying to execute a Stop event on a multithreaded
       slave could cause unwanted updates to the relay log, leading
       the slave to lose synchronization with the master. (Bug
       #14737388)

     * Replication: Internal objects used for relay log information
       were only partially deleted before freeing their memory. (Bug
       #14677824)

     * Replication: When the server starts, it checks whether
       semisynchronous replication has been enabled without a lock,
       and, if so, it takes the lock, then tests again. Disabling
       semisynchronous replication following the first of the these
       tests, but prior to the second one, could lead to a crash of
       the server. (Bug #14511533, Bug #66411)

     * Replication: It was possible in certain cases---immediately
       after detecting an EOF in the dump thread read event loop, and
       before deciding whether to change to a new binary log
       file---for new events to be written to the binary log before
       this decision was made. If log rotation occurred at this time,
       any events that occurred following EOF detection were dropped,
       resulting in loss of data. Now in such cases, steps are taken
       to make sure that all events are processed before allowing the
       log rotation to take place. (Bug #13545447, Bug #67929)
       References: See also Bug #16016886.

     * Replication: It was possible for the MASTER_POS_WAIT()
       function to return prematurely following a CHANGE MASTER TO
       statement that updated the RELAY_LOG_POS or RELAY_LOG_NAME.
       This could happen because CHANGE MASTER TO did not update the
       master log position in such cases, causing MASTER_POS_WAIT()
       to read an invalid log position and to return immediately.
       To fix this problem, the master log position is flagged as
       invalid until the position is set to a valid value when the
       SQL thread reads the first event, after which it is flagged as
       valid. Functions such as MASTER_POS_WAIT() now defer any
       comparison with the master log position until a valid value
       can be obtained (that is, after the first event following the
       CHANGE MASTER TO statement has been applied). (Bug #11766010,
       Bug #59037)

     * Replication: If the disk becomes full while writing to the
       binary log, the server hangs until space is freed up manually.
       It was possible after this was done for the MySQL server to
       fail, due to an internal status value being set when not
       needed. Now in such cases, rather than trying to set this
       status, a warning is written in the error log instead. (Bug
       #11753923, Bug #45449)

     * Replication: The binary log and relay log files used the name
       of the PID file instead of the host name as the basename. (Bug
       #11753843, Bug #45359)

     * Microsoft Windows: In Shared Memory mode
       (http://dev.mysql.com/doc/refman/5.7/en/server-options.html#op
       tion_mysqld_shared-memory), the MySQL Server could crash when
       receiving requests from multiple threads. (Bug #13934876)

     * Windows MSI installers for MySQL 5.7 had a 5.6 upgrade code,
       not a 5.7 upgrade code. (Bug #16445344)

     * SHOW ENGINE PERFORMANCE_SCHEMA STATUS could report incorrect
       memory-allocation values when the correct values exceeded 4GB.
       (Bug #16414644)

     * Performance Schema statement tokenization overhead was
       reduced. (Bug #16382260)

     * A long database name in a GRANT statement could cause the
       server to exit. (Bug #16372927)

     * The server could exit if a prepared statement attempted to
       create a table using the name of an existing view while an SQL
       handler was opened. (Bug #16385711)

     * For debug builds, checking of password constraints could raise
       an assertion for statements that updated passwords. (Bug
       #16289303)

     * The BUILD-CMAKE file in MySQL distributions was updated with
       the correct URL for CMake information. (Bug #16328024)

     * A Valgrind failure could occur if a CREATE USER statement was
       logged to the general query log and the old_passwords system
       variable was set to 2. (Bug #16300620)

     * The optimizer's attempt to remove redundant subquery clauses
       raised an assertion when executing a prepared statement with a
       subquery in the ON clause of a join in a subquery. (Bug
       #16318585)
       References: This bug is a regression of Bug #15875919.

     * Very small join_buffer_size values could cause an assertion to
       be raised. (Bug #16328373)

     * Some aggregate queries attempted to allocate excessive memory.
       (Bug #16343992)

     * Incorrect results were returned if a query contained a
       subquery in an IN clause which contained an XOR operation in
       the WHERE clause. (Bug #16311231)

     * For debug builds, an assertion could be raised if a statement
       failed with autocommit enabled just before an XA START
       statement was issued. (Bug #16341673)

     * Conversion of numeric values to BIT could yield unexpected
       results. (Bug #16271540)

     * Certain legal HAVING clauses were rejected as invalid. (Bug
       #16221433)

     * Fixed warnings when compiling with XCode 4.6. Fixed warnings
       when compiling when the _XOPEN_SOURCE or isoctal macro was
       already defined in the environment. (Bug #16265300, Bug
       #60911, Bug #12407384)

     * Queries using range predicates that were evaluated using the
       LooseScan semi-join strategy could return duplicate rows. (Bug
       #16221623)
       References: This bug is a regression of Bug #14728469.

     * For upgrade operations, RPM packages produced unnecessary
       errors about being unable to access .err files. (Bug
       #16235828)

     * In the range optimizer, an index merge failure could cause a
       server exit. (Bug #16241773)

     * For debug builds, the server could exit due to incorrect
       calculation of applicable indexes for a join that involved
       const tables. (Bug #16165832)

     * The Performance Schema could return incorrect values for the
       PROCESSLIST_INFO column of the threads table. (Bug #16215165)

     * Invocation of the range optimizer for a NULL select caused the
       server to exit. (Bug #16192219)

     * mysql_config --libs displayed incorrect output. (Bug
       #16200717)

     * For a CREATE TABLE (... col_name TIMESTAMP DEFAULT
       CURRENT_TIMESTAMP ...) ... SELECT statement for which the
       SELECT did not provide a value for the TIMESTAMP column, that
       column was set to '0000-00-00 00:00:00', not the current
       timestamp. (Bug #16163936)

     * yaSSL did not perform proper padding checks, but instead
       examined only the last byte of plaintext and used it to
       determine how many bytes to remove. (Bug #16218104)

     * Using GROUP BY WITH ROLLUP in a prepared statement could cause
       the server to exit. (Bug #16163596)

     * References to the unused SIGNAL_WITH_VIO_SHUTDOWN macro in the
       CMake files were removed. (Bug #16066150)

     * Setting the slave_rows_search_algorithms system variable to an
       inappropriate value could cause the server to exit. (Bug
       #16074161)

     * Directory name manipulation could result in stack overflow on
       Mac OS X and Windows. (Bug #16066243)

     * For debug builds, if the server was started with binary
       logging disabled, executing SHOW RELAYLOG EVENTS from within a
       stored procedure raised an assertion. (Bug #16043173)

     * The query parser leaked memory for some syntax errors. (Bug
       #16040022)

     * With the thread pool plugin enabled, large numbers of
       connections could lead to a Valgrind panic or failure of
       clients to be able to connect. (Bug #16088658, Bug #16196591)

     * The server executed EXPLAIN FORMAT=JSON for some malformed
       queries improperly. (Bug #16078557)

     * Performance Schema instrumentation was missing for slave
       worker threads. (Bug #16083949)

     * If the error for a failed CACHE INDEX statement index within a
       stored program was processed by a condition handler, a
       malformed packet and "Command out of sync" error occurred.
       (Bug #16076180)

     * The initial test database contained a dummy.bak file that
       prevented DROP DATABASE from working. This file is no longer
       included. Also, a db.opt file is now included that contains
       these lines:
default-character-set=latin1
default-collation=latin1_swedish_ci
       (Bug #16062056)

     * Setting a system variable to DEFAULT could cause the server to
       exit. (Bug #16044655)

     * SET PASSWORD and GRANT ... IDENTIFIED BY have no effect on the
       password of a user who is authenticated using an
       authentication plugin that accesses passwords stored
       externally to the mysql.user table. But attempts to change the
       password of such a user produced no warning, leading to the
       impression that the password had been changed when it was not.
       Now MySQL issues an ER_SET_PASSWORD_AUTH_PLUGIN warning to
       indicate that the attempt was ignored. (Bug #16072004)

     * For debug builds, creating an InnoDB table in strict SQL mode
       that violated the maximum key length limit caused the server
       to exit. (Bug #16035659)

     * Issuing a PREPARE statement using certain combinations of
       stored functions and user variables caused the server to exit.
       (Bug #16056537)

     * Instances of #ifdef WITH_MYISAMMRG_STORAGE_ENGINE and #ifdef
       WITH_CSV_STORAGE_ENGINE in the server source code were removed
       because the CSV and MERGE storage engine plugins are
       mandatory. (Bug #15997345)

     * A mysys library string-formatting routine could mishandle
       width specifiers. (Bug #15960005)

     * The --character-set-server option could set connection
       character set system variables to values such as ucs2 that are
       not permitted. (Bug #15985752)

     * During shutdown, the server could attempt to lock an
       uninitialized mutex. (Bug #16016493)

     * The --default-authentication-plugin option permitted invalid
       plugin values, and did not always set the old_passwords system
       variable to a value appropriate for the named plugin. (Bug
       #16014394)

     * For debug builds, executing a statement within a trigger or
       stored function that caused an implicit commit raised an
       assertion. (Bug #15985318)

     * Under some circumstances, mysql --secure-auth permitted
       passwords to be sent to the server using the old (pre-4.1)
       hashing format. (Bug #15977433)

     * With index condition pushdown enabled, queries for which the
       pushed-down condition contained no columns in the used index
       could be slow. (Bug #15896009)

     * Table creation operations added entries to the Performance
       Schema file_instances table, but these were not always removed
       for table drop operations. (Bug #15927620)

     * In special cases, the optimizer did not consider indexes that
       were applicable to query processing, resulting in potentially
       suboptimal execution and incorrect EXPLAIN output. (Bug
       #15849135, Bug #16094171)

     * A query with an EXISTS/IN/ALL/ANY subquery with an ORDER BY
       clause ordering by an outer column of type BLOB that is not in
       the select list caused an assertion to fire. (Bug #15875919)
       References: See also Bug #14728142.

     * Queries in the query cache involving a given table were
       incorrectly invalidated if a TEMPORARY table of the same name
       was dropped. (Bug #14839743)

     * The optimizer could return nonmatching records for queries
       that used ref access on string data types. (Bug #14826522)
       References: See also Bug #14682735.

     * Failure of CREATE SERVER due to a missing or read-only
       mysql.servers table resulted in a memory leak. (Bug #14781478)

     * Enabling the query cache during high client contention could
       cause the server to exit. (Bug #14727815)

     * Table names can be up to 64 characters, but the message string
       for the ER_TABLE_NEEDS_REBUILD and ER_TABLE_NEEDS_UPGRADE
       errors were truncating names longer than 32 characters. (Bug
       #14753226)

     * Enabling the slow query log at runtime when access permissions
       on the log file prevented the server from writing to it caused
       the server to exit. (Bug #14711347)

     * Table removal could fail and cause the server to exit for very
       long file names. (Bug #14581920)

     * The server sometimes failed to respect
       MAX_CONNECTIONS_PER_HOUR limits on user connections. (Bug
       #14627287)

     * The server could access the DEBUG_SYNC facility while closing
       temporary tables during connection shutdown, after the
       facility had been cleaned up, leading to an assertion being
       raised. (Bug #14626800)

     * The optimizer could return incorrect results after
       transforming an IN subquery with aggregate functions to an
       EXISTS subquery. (Bug #14586710)

     * If the optimizer calculated a row count of zero for the inner
       table of an outer join, it could not determine proper ordering
       for the following tables. (Bug #14628746)

     * When a client program loses the connection to the MySQL server
       or if the server begins a shutdown after the client has
       executed mysql_stmt_prepare(), the next mysql_stmt_prepare()
       returns an error (as expected) but subsequent
       mysql_stmt_execute() calls crash the client. (Bug #14553380)

     * Previously, if multiple --login-path options were given,
       mysql_config_editor ignored all but the last one. Now multiple
       --login-path options result in an error. (Bug #14551712)

     * If MySQL server was started with options to enable the general
       query log or slow query log, but access permissions on the log
       file prevented the server from writing to it, the server
       started with an error message indicating that logging was off
       and that the server needed to be restarted after the problem
       was corrected. This was incorrect because it is also possible
       to set the logging variables again at runtime (without a
       restart) after correcting the problem. The error message now
       indicates this possibility. (Bug #14512467)

     * For debug builds, creating a TEMPORARY table inside a trigger
       caused the server to exit. (Bug #14493938)

     * SHOW COLUMNS on a view defined as a UNION of Geometry columns
       could cause the server to exit. (Bug #14362617)

     * The sha256_password_private_key_path and
       sha256_password_public_key_path system variables indicate key
       files for the sha256_password authentication plugin, but the
       server failed to properly check whether the key files were
       valid. Now in the event that either key file is invalid, the
       server logs an error and exits. (Bug #14360513)

     * SET var_name = VALUES(col_name) could cause the server to
       exit. This syntax is now prohibited because in SET context
       there is no column name and the statement returns
       ER_BAD_FIELD_ERROR. (Bug #14211565)

     * The COM_CHANGE_USER command in the client/server protocol did
       not properly use the character set number in the command
       packet, leading to incorrect character set conversion of other
       values in the packet. (Bug #14163155)

     * If the server was started with --skip-grant-tables, the CREATE
       EVENT and ALTER EVENT statements resulted in a memory leak.
       (Bug #14059662)

     * Invoking the FORMAT() function with a locale and a very large
       number could cause the server to exit. (Bug #14040155)

     * For debug builds, improper handling for AUTO_INCREMENT value
       overflow could cause the server to exit. (Bug #13875572)

     * Certain plugin-related conditions can make a user account
       unusable:

          + The account requires an authentication plugin that is not
            loaded.

          + The account requires the sha256_password authentication
            plugin but the server was started with neither SSL nor
            RSA enabled as required by this plugin.
       The server now checks those conditions by default and produces
       warnings for unusable accounts. This checking slows down
       server initialization and FLUSH PRIVILEGES, so it is made
       optional by means of the new validate_user_plugins system
       variable. This variable is enabled by default, but if you do
       not require the additional checking, you can disable it at
       startup to avoid the performance decrement. (Bug #13010061,
       Bug #14506305)

     * Passing an unknown time zone specification to CONVERT_TZ()
       resulted in a memory leak. (Bug #12347040)

     * The obsolete linuxthreads.txt and glibc-2.2.5.patch files in
       the Docs directory of MySQL distributions have been removed.
       (Bug #11766326)

     * mysql_install_db did not escape '_' in the host name for
       statements written to the grant tables. (Bug #11746817)

     * The server could exit if built to permit a maximum number of
       indexes per table larger than 64.
       In the course of fixing this problem, a -DMAX_INDEXES=N CMake
       option was added to permit building the server to support a
       larger maximum number of indexes per table. The default is 64.
       The maximum is 255. Values smaller than 64 are ignored and the
       default of 64 is used. (Bug #11761614)

     * Source code in the mysys library for the my_malloc_lock and
       my_free_lock memory-locking APIs was never used and has been
       removed. (Bug #54662, Bug #11762107)

     * mysqld_safe used the nonportable -e test construct. (Bug
       #67976, Bug #16046140)

     * An out-of-memory condition could occur while handling an
       out-of-memory error, leading to recursion in error handling.
       (Bug #49514, Bug #11757464)

     * The optimizer used loose index scan for some queries for which
       this access method is inapplicable. (Bug #42785, Bug
       #11751794)

     * If a dump file contained a view with one character set and
       collation defined on a view with a different character set and
       collation, attempts to restore the dump file failed with an
       "illegal mix of collations" error. (Bug #65382, Bug #14117025)

     * If the server failed to read errmsg.sys, it could exit with a
       segmentation fault. (Bug #53393, Bug #11760944)

     * The REPLACE() function produced incorrect results when a user
       variable was supplied as an argument and the operation was
       performed on multiple rows. (Bug #49271, Bug #11757250)

     * The output for SHOW CREATE VIEW could vary depending on the
       DEFINER account privileges. (Bug #34553, Bug #11747931)

     * UNION type conversion could incorrectly turn unsigned values
       into signed values. (Bug #49003, Bug #11757005)

     * If one thread was rebuilding a result for the query cache,
       other threads in the middle of using the previous result could
       fail to discard the old result properly. For debug builds,
       this raised an assertion. (Bug #66781, Bug #14631798)

     * UNION ALL on BLOB columns could produce incorrect results.
       (Bug #50136, Bug #11758009)

     * View access in low memory conditions could raise a debugging
       assertion. (Bug #39307, Bug #11749556)

     * Attempts to create a trigger for which a trigger with the same
       action time and event already existed resulted in an
       ER_NOT_SUPPORTED_YET error rather than an
       ER_TRG_ALREADY_EXISTS error. (Bug #67357, Bug #14801721)

     * Queries with many values in a IN() clause were slow due to
       inclusion of debugging code in non-debugging builds. (Bug
       #68046, Bug #16078212)
       References: See also Bug #58731, Bug #11765737.

     * When a view definition contained a special character in the
       SEPARATOR clause of the GROUP_CONCAT() aggregate function,
       mysqldump created an invalid view definition that produced an
       error when the dump file was reloaded. (Bug #60920, Bug
       #12395512)

     * Setting max_connections to a value less than the current
       number of open connections caused the server to exit. (Bug
       #44100, Bug #11752803)

     * Some table I/O performed by the server when calling a storage
       engine were missing from the statistics collected by the
       Performance Schema. (Bug #68180, Bug #16222630)

     * For debug builds, some queries with SELECT ... FROM DUAL
       nested subqueries raised an assertion. (Bug #60305, Bug
       #11827369)

     * Nonspatial indexes only support exact-match lookups for
       spatial columns, but the optimizer incorrectly used range
       access in some cases, leading to incorrect results. (Bug
       #67889, Bug #15993693)

     * If mysql is built with the bundled libedit library, the
       library is built as static code, to avoid linking to a
       different dynamic version at runtime. Dynamic linking could
       result in use of a different, incompatible version and a
       segmentation fault. (Bug #68231, Bug #16296509)

     * SLEEP() produced no warning or error for NULL or negative
       arguments. Now it produces a warning, or an error in strict
       SQL mode. (Bug #67548, Bug #15859462)

     * The --log-slow-admin-statements and
       --log-slow-slave-statements command options now are exposed at
       runtime as the log_slow_admin_statements and
       log_slow_slave_statements system variables. Their values can
       be examined using SHOW VARIABLES. The variables are dynamic,
       so their values can can be set at runtime. (The options were
       actually replaced by the system variables, but as system
       variables can be set at server startup, no option
       functionality is lost.) (Bug #59860, Bug #11766693)

     * For arguments with fractional seconds greater than six
       decimals, SEC_TO_TIME() truncated, rather than rounding as it
       should have. (Bug #68061, Bug #16093024)

     * MySQL failed to build if configured with WITH_LIBWRAP enabled.
       (Bug #67018, Bug #16342793)

     * If the server was started without a --datadir option, SHOW
       VARIABLES could show an empty value for the datadir system
       variable. (Bug #60995, Bug #12546953)

     * If a table had rows in the
       INFORMATION_SCHEMA.INNODB_CMP_PER_INDEX table, dropping the
       table did not remove those rows. (Bug #67283, Bug #14779330)

     * Configuring with -DWITH_SSL=/path/to/openssl resulted in link
       errors due to selection of the incorrect libcrypto. (Bug
       #68277, Bug #16284051)

     * ALTER TABLE tbl_name ADD COLUMN col_name TIMESTAMP DEFAULT
       CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP inserted
       0000-00-00 00:00:00 rather than the current timestamp if the
       alteration was done in place rather than by making a table
       copy. (Bug #68040, Bug #16076089)

     * If the server was started with --skip-grant-tables, ALTER USER
       ... PASSWORD EXPIRE caused the server to exit. (Bug #68300,
       Bug #16295905)

     * CMake did not check whether the system zlib had certain
       functions required for MySQL, resulting in build errors. Now
       it checks and falls back to the bundled zlib if the functions
       are missing. (Bug #65856, Bug #14300733)

     * mysql_install_db did not work in Solaris 10 sparse root zones.
       (Bug #68117, Bug #16197860)

     * For EXPLAIN DELETE and EXPLAIN UPDATE the possible_keys column
       listed all indexes, not just the applicable indexes. (Bug
       #67830, Bug #15972078)

     * The Perl version of mysql_install_db mishandled some error
       messages. (Bug #68118, Bug #16197542)

     * Handling of SQL_CALC_FOUND_ROWS in combination with ORDER BY
       and LIMIT could lead to incorrect results for FOUND_ROWS().
       (Bug #68458, Bug #16383173)

     * The server did not enforce the port or report_port upper limit
       of 65,535 and truncated larger values. (Bug #67956, Bug
       #16035522)

     * Adding an ORDER BY clause following an IN subquery could cause
       duplicate rows to be returned. (Bug #68330, Bug #16308085)

     * If INET6_NTOA() or INET6_ATON() returned NULL for a row in a
       result set, following rows also returned NULL. (Bug #68454,
       Bug #16373973)

     * If XA support was activated by multiple storage engines, the
       server would exit. (Bug #47134, Bug #11755370)

     * A statement with an aggregated, nongrouped outer query and an
       aggregated, nongrouped subquery in the SELECT list could
       return incorrect results. (Bug #68372, Bug #16325175)

     * The SQL_NO_CACHE keyword is supposed to prevent the server
       from checking the query cache to see whether the query result
       is already cached, and to prevent it from caching the query
       result. However, the query cache check was suppressed only if
       SQL_NO_CACHE was preceded and followed by space characters.
       (For example, the server checked the cache if the keyword was
       followed by a newline.) Now the parser requires that the
       preceding and following characters be whitespace characters,
       not spaces. (Bug #64164, Bug #13641256)

     * With explicit_defaults_for_timestamp enabled, inserting NULL
       into a TIMESTAMP NOT NULL column now produces an error (as it
       already did for other NOT NULL data types), instead of
       inserting the current timestamp. (Bug #68472, Bug #16394472)

     * Use of KILL to kill a statement in another session could in
       some cases cause that session to return an incorrect error
       code. (Bug #45679, Bug #11754124)

     * If a column is declared as NOT NULL, it is not permitted to
       insert NULL into the column or update it to NULL. However,
       this constraint was enforced even if there was a BEFORE INSERT
       (or BEFORE UPDATE trigger) that set the column to a non-NULL
       value. Now the constraint is checked at the end of the
       statement, per the SQL standard. (Bug #6295, Bug #11744964)

     * On Windows, the log_error system variable did not accurately
       reflect the error log file name in some cases. For example, if
       the server was started without --console or --log-error, the
       default is to log to host_name.err in the data directory, but
       log_error remained blank.
       Now log_error should be nonblank and reflect the log file name
       in all cases, on all platforms. The value is stderr if the
       server does not write error messages to a file and sends them
       to the console (standard error output) instead. In particular,
       on Windows, --console overrides use of an error log and sends
       error messages to the console, so log_error will be set to
       stderr. (Bug #8307, Bug #11745049)

     * Important Change: Formerly, the ExtractValue() and UpdateXML()
       functions supported a maximum length of 127 characters for
       XPath expressions supplied to them as arguments. This
       limitation has now been removed. (Bug #13007062, Bug #62429)

     * InnoDB: Creating and altering tables repeatedly would result
       in a memory leak that was due to a duplicate key error. The
       duplicate key error occurred because the
       row_merge_build_indexes function did not call
       row_fts_psort_info_destroy often enough. As full-text search
       indexes were created with a unique index, the unique index
       would fail due to the duplicate key error, and full-text
       search build resource would not be released. (Bug #14759111)

     * InnoDB: InnoDB IO threads within Performance Schema were
       exposed with the following name: "io_handler_thread". This fix
       implements specific keys such as io_read_handler_thread,
       io_write_handler_thread, io_ibuf_handler_thread to
       differentiate InnoDB IO threads within Performance Schema.
       (Bug #14670810)

     * InnoDB: This fix addresses an assert condition that would
       occur when inserting large BLOBs into tablespaces with a 4KB
       physical page size or into some compressed tables. Extents
       would not be allocated soon enough for tablespaces with
       smaller physical page sizes. (Bug #14520559)

     * InnoDB: On Linux systems, certain I/O requests that read or
       wrote fewer than the requested number of bytes could cause the
       server to crash. This issue could happen more frequently with
       asynchronous I/O
       (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_asy
       nchronous_io) requests. The messages did not clearly identify
       what type of error occurred:
InnoDB: Operating system error number 0 in a file operation.
InnoDB: Error number 0 means 'Success'.
       With this fix, MySQL retries the operation several times
       before giving up. (The number of retries is defined by the
       constant NUM_RETRIES_ON_PARTIAL_IO in the source code, default
       value 10.) (Bug #11761646, Bug #54160)

     * Partitioning: When the server is started with
       --skip-partition, it should reject DDL or DML statements on
       partitioned tables. However, for DROP TABLE, the server
       dropped the .frm file, and for RENAME TABLE, the server
       renamed the .frm file. (Bug #11763795)

     * Replication: mysqlbinlog did not properly decode DECIMAL
       values in a row-based binary log. This could cause invalid
       values to be printed out for DECIMAL columns. (Bug #14309019)

     * Replication: When using mysqlbinlog with the --verbose option
       to read a binary log written by a MySQL server using row-based
       or mixed-format logging, invalid SQL could be produced when
       comments appeared inside BINLOG statements. One way in which
       this could happen was when a function that updated data was
       used within an INSERT ... SELECT statement. (Bug #12889121)

     * Replication: mysql_upgrade on the master broke replication
       when the slave was run with --log-output equal to FILE or
       NONE. (Bug #11763447)

     * Replication: Issuing STOP SLAVE caused a spurious Error
       reading packet from server: Lost connection to MySQL server
       during query message to be written to the error log. (Bug
       #11761457, Bug #12977988, Bug #53955)

     * Replication: When an error occurs in the slave SQL thread,
       this causes the Slave_SQL_Error and Slave_SQL_Errno columns
       from SHOW SLAVE STATUS to display the reason for the error.
       The error number should be one of the usual constants ER_*
       defined in sql/share/errmsg.txt, and the error message should
       be the corresponding string. However, in some cases,
       Slave_SQL_Errno was set to something other than an ER_*
       number, and Slave_SQL_Error to a hard-coded error message
       rather than a translatable string from sql/share/errmsg.txt.
       Now all errors shown by SHOW SLAVE STATUS originate in
       sql/share/errmsg.txt, as expected. (Bug #11760365, Bug #52768)

     * Microsoft Windows: On Microsoft Windows, CMake entries for
       POSIX API's not found on Microsoft Windows were added to the
       CMake cache. This decreases the number of expected "Not found"
       errors while compiling MySQL. (Bug #14790333)

     * Microsoft Windows: On Microsoft Windows, queries referring to
       a table with invalid characters would search the system for
       invalid file names. The generated system error code
       (ERROR_INVALID_NAME) was not recognized by MySQL, so this
       unknown error would be reported to the server log as "ERRNO:
       22 - INVALID ARGUMENT". MySQL now recognizes these errors and
       reports them as the table does not existing, and it no longer
       logs them to the server error log. (Bug #14642248)

     * Microsoft Windows: On Windows, starting the server with
       --log-error and --console caused the server to write to the
       log file but not the console. Before MySQL 5.5.3, this
       occurred only if --log-error was specified after --console.
       Now, --console overrides --log-error no matter the option
       order so that --console produces console output in all cases.
       (Bug #14207773, Bug #65592)

     * Microsoft Windows: It was possible to specify a Named Pipe
       (http://dev.mysql.com/doc/refman/5.7/en/server-options.html#op
       tion_mysqld_enable-named-pipe) that was already in use. This
       is no longer allowed, as an error is now emitted and the
       process is aborted. After mysqld.exe was started in Named Pipe
       mode with a pipe name that was already used by a different
       instance, neither instance was able to shut down properly when
       a shutdown command was received from a TCP socket in any of
       the processes. Therefore, mysqld.exe was not terminated. (Bug
       #13891058, Bug #61885)

     * Microsoft Windows: On Microsoft Windows, a failed API or
       function call in mysqld.exe could sometimes report the error
       code 22, instead of the proper error code. (Bug #11763004)

     * Joins of exactly 32 tables and containing a HAVING clause
       returned an empty result. (Bug #15972635)

     * The parser rejected some legal UNION statements. (Bug
       #14730856)

     * Setting thread_cache_size to a negative value at server
       startup resulted in a value of 16384 rather than 0. (Bug
       #14683107)

     * The return value from IS_USED_LOCK() was reported using the
       wrong data type. (Bug #14575699)

     * There was no warning at startup if the server was started with
       an invalid query_cache_size value. (Bug #14576423)

     * Activation of a stored program handler did not preserve the
       current diagnostics stack. (Bug #14342913)

     * In debug builds, killing a HELP statement caused an assertion
       to be raised. (Bug #14221840)

     * If an error occurred during evaluation of the BEFORE
       expression of a PURGE BINARY LOGS BEFORE statement, the
       statement did not abort as it should have and later raised an
       assertion. (Bug #14215847)

     * For the index merge access method, the optimizer could make a
       suboptimal choice of indexes to use. (Bug #14095506)

     * An assertion could be raised if the attempt to open the .frm
       file for a temporary table failed. (Bug #13359247)

     * If the state of the Event Scheduler was changed during server
       shutdown, the server could crash. (Bug #13002460)

     * When storing the definition for a view that used the UPPER()
       or LOWER() function, the function call was replaced by UCASE()
       or LCASE(), respectively (as shown in the output of SHOW
       CREATE VIEW). This was in spite of the fact that UPPER() and
       LOWER() are standard, with UCASE() and LCASE() being MySQL
       synonyms for these. This made it more difficult to move
       databases between MySQL and other database systems.
       With this fix, calls to UPPER() and LOWER() within views are
       no longer rewritten when storing their definitions; instead,
       UCASE() is now rewritten as UPPER() in stored view
       definitions, and LCASE() as LOWER(), which increases the
       portability of the views. (Bug #12844279)

     * For queries that accessed an INFORMATION_SCHEMA table in a
       subquery, and attempt to lock a mutex that had already been
       locked could cause a server crash. (Bug #11765744)

     * The Range checked for each record optimization is now used for
       conditions with outer query references. (Bug #11750963)

     * An INSERT INTO ... SELECT statement that inserted no rows
       unnecessarily invalidated statements in the query cache that
       used the target table. (Bug #50065, Bug #11757947)

     * The server refused client connections while executing FLUSH
       PRIVILEGES. (Bug #63178, Bug #13418619)

     * References to a stored function without a database name
       qualifier while there was no default database resulted in an
       ER_SP_DOES_NOT_EXIST error rather than ER_NO_DB_ERROR. (Bug
       #64692, Bug #13864485)

     * Concurrent inserts were blocked by selects if the inserts were
       generated from within a stored procedure. (Bug #58689, Bug
       #11765698)

     * Concurrent execution of DROP DATABASE and any of CREATE
       FUNCTION, CREATE PROCEDURE, or CREATE EVENT could be written
       to the binary log in the wrong order, causing replication
       failure. (Bug #65428, Bug #14127220)

     * INSERT INTO ... SELECT ... ON DUPLICATE KEY UPDATE and LOAD
       DATA CONCURRENT REPLACE took too weak a lock, leading to the
       possibility of concurrent SELECT statements returning
       inconsistent results. (Bug #38046, Bug #11749055)

     * If read_only is enabled, it is still permitted to create
       TEMPORARY tables. But in this case, a non-TEMPORARY table with
       the same name could also be created, which should not be
       permitted. (Bug #64992, Bug #13969578)

     * Enabling the session value of low_priority_updates had no
       effect for INSERT statements. (Bug #64892, Bug #13939940)

     * An event was not dropped from the mysql.event table under
       these circumstances: The event was created while the event
       scheduler was enabled; the scheduler was disabled and
       re-enabled; the event expiration time was reached. (Bug
       #34804, Bug #11748012)

     * Using ALTER TABLE to rename a table to . resulted in a table
       with no name. (Bug #49636, Bug #11757569)

     * SHOW CREATE VIEW failed if the tables underlying the view were
       changed. (Bug #61718, Bug #12762393)

     * SHOW GLOBAL STATUS caused performance problems on busy servers
       due to lock contention. (Bug #42930, Bug #11751904)

     * For a view defined on a UNION, the server could create an
       invalid view definition. (Bug #65388, Bug #14117018)

     * For queries using ref access on string data types, the ref
       access condition could be evaluated again as part of the query
       condition or pushed down as an index condition to the storage
       engine. (Bug #66983, Bug #14682735)

     * For an ALTER TABLE statement that renamed or changed the
       default value of a BINARY column, the alteration was done
       using a table copy and not in place. (Bug #67141, Bug
       #14735373)

     * A view was created with an incorrect definition if the WHERE
       clause contained string literals and character_set_client and
       character_set_connection were set to different character sets.
       (Bug #63094, Bug #13520710)

=======================================================================

Changes in MySQL 5.7.1 (23 April 2013, Milestone 11)

   Note

   This is a milestone release, for use at your own risk. Significant
   development changes take place in milestone releases and you may
   encounter compatibility issues, such as data format changes that
   require attention in addition to the usual procedure of running
   mysql_upgrade. For example, you may find it necessary to dump your
   data with mysqldump before the upgrade and reload it afterward.

   Functionality Added or Changed

     * Performance: String hashing overhead was reduced. This also
       improves performance for metadata locking, the table
       definition cache, and Performance Schema table I/O and file
       I/O instrumentation. (Bug #13944392)

     * Incompatible Change: SHOW ENGINE PERFORMANCE_SCHEMA STATUS
       output used a mix of row_count and count attributes. These are
       now all count. Similarly, the output used a mix of row_size
       and size attributes. These are now all size. (Bug #16165468)

     * InnoDB: Online index renaming is supported by ALTER TABLE,
       which now includes a RENAME INDEX clause, as shown in the
       following example: "ALTER TABLE t RENAME INDEX i1 TO i2",
       where i1 is the current name of the index and i2 is the new
       name.
       The result of "ALTER TABLE t RENAME INDEX i1 TO i2" would be a
       table with contents and structure that is identical to the old
       version of "t1" except for the index name, which is now "i2"
       instead of "i1".

     * InnoDB: You can now increase VARCHAR size online through ALTER
       TABLE ...ALGORITHM=INPLACE, CHANGE COLUMN...VARCHAR(). VARCHAR
       size may be increased from a value less than 255 bytes up to a
       value equal to or less than 255 bytes. You may also increase
       VARCHAR size online from a starting value greater than 255
       bytes (Bug#15863023).
       Note
       Decreasing VARCHAR size online is not supported, nor is
       increasing VARCHAR size online from a value less than 256
       bytes to a value greater than 256 bytes.

     * InnoDB: DDL performance for InnoDB temporary tables is
       improved through optimization of CREATE TABLE, DROP TABLE,
       TRUNCATE TABLE, ALTER TABLE ... IMPORT TABLESPACE, and ALTER
       TABLE ...DISCARD TABLESPACE statements.

     * InnoDB: Added support for spatial data types currently
       supported by MySQL including POINT, LINE_STRING, POLYGON,
       MULTI_POINT, MULTI_POLYGON, MULTI_LINE_STRING,
       GEOMETRY_COLLECTION, and GEOMETRY.
       Prior to this release, InnoDB would store spatial data, except
       for POINT, as binary BLOB data. BLOB remains the underlying
       data type but spatial data types are now mapped to a new
       InnoDB internal data type, DATA_GEOMETRY. With BLOB as the
       underlying data type, a prefix index can still be used on the
       GEOMETRY data column.

     * InnoDB: Added a separate tablespace for all non-compressed
       user and system-generated temporary tables. The new
       tablespace, which is always recreated on server startup,
       provides persistent storage for temporary table
       meta-information. Persistent meta-information enables proper
       cleanup in crash recovery scenarios. Additionally, a separate
       tablespace for temporary tables avoids having to store
       persistent meta-information in system tablespaces.
       The new tablespace, ibtmp1, is located in the /tmp directory
       by default. A newly added configuration file option,
       --innodb_temp_data_file_path, allows for a user-defined
       temporary data file path.

     * Replication: An Auto_Position column has been added to the
       output generated by SHOW SLAVE STATUS. The value of this
       column shows whether replication autopositioning is in use. If
       autopositioning is enabled---that is, if MASTER_AUTO_POSITION
       = 1 was set by the last successful CHANGE MASTER TO statement
       that was executed on the slave---then the column's value is 1;
       if not, then the value is 0. (Bug #15992220)

     * Replication: The functions GTID_SUBTRACT() and GTID_SUBSET()
       were formerly available in libmysqld only when it was built
       with replication support. Now these functions are always
       available when using this library, regardless of how it was
       built.

     * MySQL no longer uses the default OpenSSL compression. (Bug
       #16235681)

     * There is now a distinct error code
       (ER_MUST_CHANGE_PASSWORD_LOGIN) for the error sent by the
       server to a client authenticating with an expired password.
       (Bug #16102943)

     * In RPM packages built for Unbreakable Linux Network,
       libmysqld.so now has a version number. (Bug #15972480)

     * Error messages for ALTER TABLE statement using a LOCK or
       ALGORITHM value not supported for the given operation were
       very generic. The server now produces more informative
       messages. (Bug #15902911)

     * If a client with an expired password connected but
       old_passwords was not the value required to select the
       password hashing format appropriate for the client account,
       there was no way for the client to determine the proper value.
       Now the server automatically sets the session old_passwords
       value appropriately for the account password. (Bug #15892194)

     * mysql_config_editor now supports --port and --socket options
       for specifying TCP/IP port number and Unix socket file name.
       (Bug #15851247)

     * mysqldump now supports an --ignore-error option. The option
       value is a comma-separated list of error numbers specifying
       the errors to ignore during mysqldump execution. If the
       --force option is also given to ignore all errors, --force
       takes precedence. (Bug #15855723)

     * mysqlcheck has a new --skip-database option. The option value
       is the name of a database (case sensitive) for which checks
       should be skipped.
       mysql_upgrade uses this option to upgrade the system tables in
       the mysql database before tables in other databases: It
       upgrade the mysql database, then all databases except the
       mysql database. This avoids problems that can occur if user
       tables are upgraded before the system tables. (Bug #14697538)

     * The validate_password_policy_number system variable was
       renamed to validate_password_policy. (Bug #14588121)

     * Previously, on Linux the server failed to perform stack
       backtrace attempts for versions of glibc older than the
       current minimum supported version (2.3). Now on such attempts
       the server displays a message that the glibc version is too
       old to support backtracing. (Bug #14475946)

     * In JSON-format EXPLAIN output, the attached_condition
       information for subqueries now includes select# to indicate
       the relative order of subquery execution. (Bug #13897507)

     * The following changes were made to the sandbox mode that the
       server uses to handle client connections for accounts with
       expired passwords:

          + There is a new disconnect_on_expired_passwords system
            variable (default: enabled). This controls how the server
            treats expired-password accounts.

          + Two flags were added to the C API client library:
            MYSQL_OPT_CAN_HANDLE_EXPIRED_PASSWORDS for
            mysql_options() and CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS
            for mysql_real_connect(). Each flag enables a client
            program to indicate whether it can handle sandbox mode
            for accounts with expired passwords.
            MYSQL_OPT_CAN_HANDLE_EXPIRED_PASSWORDS is enabled for
            mysqltest unconditionally, for mysql in interactive mode,
            and for mysqladmin if the first command is password.
       For more information about how the client-side flags interact
       with disconnect_on_expired_passwords, see Password Expiration
       and Sandbox Mode
       (http://dev.mysql.com/doc/refman/5.7/en/password-expiration.ht
       ml). (Bug #67568, Bug #15874023)

     * If a user attempted to access a nonexistent column for which
       the user had no access, the server returned an error
       indicating that the column did not exist. Now the server
       returns an error indicating that the user does not have
       privileges for the column, which provides no information about
       column existence. (Bug #19947, Bug #11745788)

     * The deprecated innodb_mirrored_log_groups system variable has
       been removed.

     * The mysql client now has a --syslog option that causes
       interactive statements to be sent to the system syslog
       facility. Logging is suppressed for statements that match the
       default "ignore" pattern list ("*IDENTIFIED*:*PASSWORD*"), as
       well as statements that match any patterns specified using the
       --histignore option. For more information, see mysql Logging
       (http://dev.mysql.com/doc/refman/5.7/en/mysql-logging.html).

     * ALTER TABLE now supports a RENAME INDEX clause that renames an
       index. The change is made in place without a table-copy
       operation. See ALTER TABLE Syntax
       (http://dev.mysql.com/doc/refman/5.7/en/alter-table.html).

     * Important Change; Replication: Added the --idempotent option
       for mysqlbinlog, which causes the MySQL Server to employ
       idempotent mode. This causes suppression of all duplicate-key
       and key-not-found errors when processing updates from the
       binary log. The mode is in effect for the current mysqlbinlog
       client and client session only.

     * Important Change; Replication: SHOW SLAVE STATUS when run
       concurrently with STOP SLAVE can take a long time to execute
       if the slave SQL thread was in the midst of applying a large
       update. To fix this problem, a new NONBLOCKING option has been
       added to the SHOW SLAVE STATUS statement. When this option is
       used, SHOW SLAVE STATUS does not wait on the SQL or I/O
       threads but returns immediately. This means that the reported
       states of these threads may not be completely up to date when
       the option is used. NONBLOCKING is intended primarily for use
       by monitoring tools in which obtaining an immediate response
       is more important than having the most timely data.

     * Microsoft Windows: Windows Vista, Windows Server 2008, and
       newer support native symlinking using the mklink command. This
       makes the MySQL Server implementation of database symbolic
       links using .sym files redundant, so that mechanism is now
       removed. This change has the following implications:

          + Existing .sym files are now ignored. Database symlinks
            should be recreated using mklink. See Using Symbolic
            Links for Databases on Windows
            (http://dev.mysql.com/doc/refman/5.7/en/symbolic-links.ht
            ml#windows-symbolic-links).

          + The --symbolic-links and --skip-symbolic-links options
            and the have_symlink system variable now are meaningful
            only for Unix systems, and not for Windows.

     * The server now issues a warning if an index is created that
       duplicates an existing index, or an error in strict SQL mode.
       (Bug #37520, Bug #11748842)

     * Previously, Control+C in mysql interrupted the current
       statement if there was one, or exited mysql if not. Now
       Control+C interrupts the current statement if there was one,
       or cancels any partial input line otherwise, but does not
       exit. (Bug #66583, Bug #14554568)

     * The mysql_clear_password cleartext client-side authentication
       plugin is intended for authentication schemes that require the
       server to receive the password as entered on the client side,
       without hashing. Because the password is sent in the clear,
       this plugin should be used within the context of a secure
       connection, such as an SSL connection, to avoid exposing the
       password over the network. To make inadvertent use of this
       plugin less likely, it is now required that clients explicitly
       enable it. This can be done several ways:

          + Set the LIBMYSQL_ENABLE_CLEARTEXT_PLUGIN environment
            variable to a value that begins with 1, Y, or y. This
            enables the plugin for all client connections.

          + The mysql, mysqladmin, and mysqlslap client programs
            support an --enable-cleartext-plugin option that enables
            the plugin on a per-invocation basis.

          + The mysql_options() C API function supports a
            MYSQL_ENABLE_CLEARTEXT_PLUGIN option that enables the
            plugin on a per-connection basis. Also, any program that
            uses libmysqlclient and reads option files can enable the
            plugin by including an enable-cleartext-plugin option in
            an option group read by the client library.

     * INSERT DELAYED is no longer supported. The server recognizes
       but ignores the DELAYED keyword, handles the insert as a
       nondelayed insert, and generates an
       ER_WARN_LEGACY_SYNTAX_CONVERTED warning. ("INSERT DELAYED is
       no longer supported. The statement was converted to INSERT.").
       Similarly, REPLACE DELAYED is handled as a nondelayed replace.
       The DELAYED keyword will be removed in a future release.
       In addition, several DELAYED-related options or features were
       removed:

          + The --delayed-insert option for mysqldump.

          + The COUNT_WRITE_DELAYED, SUM_TIMER_WRITE_DELAYED,
            MIN_TIMER_WRITE_DELAYED, AVG_TIMER_WRITE_DELAYED, and
            MAX_TIMER_WRITE_DELAYED columns of the Performance Schema
            table_lock_waits_summary_by_table table.
            If you upgrade to this release of MySQL from an earlier
            version, you must run mysql_upgrade (and restart the
            server) to incorporate these changes into the
            performance_schema database.

          + mysqlbinlog no longer writes comments mentioning INSERT
            DELAYED.

     * MySQL now supports stacked diagnostics areas and GET STACKED
       DIAGNOSTICS can be used during condition handler activation to
       retrieve information from the diagnostics area that was
       current before the handler was activated. This enables
       handlers to inspect information about the condition that
       caused the handler to activate. As before, GET [CURRENT]
       DIAGNOSTICS still retrieves information about the current
       diagnostics area and can be used even if no handler is active.
       For more information, see GET DIAGNOSTICS Syntax
       (http://dev.mysql.com/doc/refman/5.7/en/get-diagnostics.html).

   Bugs Fixed

     * Performance; InnoDB: The DROP TABLE statement for a table
       using compression
       (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_com
       pression) could be slower than necessary, causing a stall for
       several seconds. MySQL was unnecessarily decompressing pages
       (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_pag
       e) in the buffer pool
       (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_buf
       fer_pool) related to the table as part of the DROP operation.
       (Bug #16067973)

     * Incompatible Change; Partitioning: Changes in the KEY
       partitioning hashing functions used with numeric, date and
       time, ENUM, and SET columns in MySQL 5.5 makes tables using
       partitioning or subpartitioning by KEY on any of the affected
       column types and created on a MySQL 5.5 or later server
       incompatible with a MySQL 5.1 server. This is because the
       partition IDs as calculated by a MySQL 5.5 or later server
       almost certainly differ from those calculated by a MySQL 5.1
       server for the same table definition and data as a result of
       the changes in these functions.
       The principal changes in the KEY partitioning implementation
       in MySQL 5.5 resulting in this issue were as follows: 1. The
       hash function used for numeric and date and time columns
       changed from binary to character-based. 2. The base used for
       hashing of ENUM and SET columns changed from latin1 ci
       characters to binary.
       The fix involves adding the capability in MySQL 5.5 and later
       to choose which type of hashing to use for KEY partitioning,
       which is implemented with a new ALGORITHM extension to the
       PARTITION BY KEY option for CREATE TABLE and ALTER TABLE.
       Specifying PARTITION BY KEY ALGORITHM=1 ([columns]) causes the
       server to use the hashing functions as implemented in MySQL
       5.1; using ALGORITHM=2 causes the server to use the hashing
       functions from MySQL 5.5 and later. ALGORITHM=2 is the
       default. Using the appropriate value for ALGORITHM, you can
       perform any of the following tasks:

          + Create KEY partitioned tables in MySQL 5.5 and later that
            are compatible with MySQL 5.1, using CREATE TABLE ...
            PARTITION BY KEY ALGORITHM=1 (...).

          + Downgrade KEY partitioned tables that were created in
            MySQL 5.5 or later to become compatible with MySQL 5.1,
            using ALTER TABLE ... PARTITION BY KEY ALGORITHM=1 (...).

          + Upgrade KEY partitioned tables originally created in
            MySQL 5.1 to use hashing as in MySQL 5.5 and later, using
            ALTER TABLE ... PARTITION BY KEY ALGORITHM=2 (...).
            Important: After such tables are upgraded, they cannot be
            used any longer with MySQL 5.1 unless they are first
            downgraded again using ALTER TABLE ... PARTITION BY KEY
            ALGORITHM=1 (...) on a MySQL server supporting this
            option.
       This syntax is not backward compatible, and causes errors in
       older versions of the MySQL server. When generating CREATE
       TABLE ... PARTITION BY KEY statements, mysqldump brackets any
       occurrence of ALGORITHM=1 or ALGORITHM=2 in conditional
       comments such that it is ignored by a MySQL server whose
       version is not at least 5.5.31. An additional consideration
       for upgrades is that MySQL 5.6 servers prior to MySQL 5.6.11
       do not ignore the ALGORITHM option in such statements when
       generated by a MySQL 5.5 server, due to the that the
       conditional comments refer to version 5.5.31; in this case,
       you must edit the dump manually and remove or comment out the
       option wherever it occurs before attempting to load it into a
       MySQL 5.6.10 or earlier MySQL 5.6 server. This is not an issue
       for dumps generated by MySQL 5.6.11 or later version of
       mysqldump, where the version used in such comments is 5.6.11.
       For more information, see ALTER TABLE Partition Operations
       (http://dev.mysql.com/doc/refman/5.7/en/alter-table-partition-
       operations.html).
       As part of this fix, a spurious assertion by InnoDB that a
       deleted row had previously been read, causing the server to
       assert on delete of a row that the row was in the wrong
       partition, was also removed. (Bug #14521864, Bug #66462, Bug
       #16093958, Bug #16274455)
       References: See also Bug #11759782.

     * Important Change; Plugin API; Replication: Because the
       behavior of the fulltext plugin may vary between MySQL
       servers, it is not possible to guarantee that statements using
       this plugin produce the same results on masters and slaves.
       For this reason, statements depending on the fulltext plugin
       are now marked as unsafe for statement-based logging. This
       means that such statements are logged using row format when
       binlog_format=MIXED, and cause a warning to be generated when
       binlog_format=STATEMENT. (Bug #11756280, Bug #45449)

     * Important Change; Replication: Executing a statement that
       performs an implicit commit but whose changes are not logged
       when gtid_next is set to any value other than AUTOMATIC is not
       permitted. Now in such cases, the statement fails with an
       error. This includes the statements in the following list:

          + CHANGE MASTER TO

          + START SLAVE

          + STOP SLAVE

          + REPAIR TABLE

          + OPTIMIZE TABLE

          + ANALYZE TABLE

          + CHECK TABLE

          + CREATE SERVER

          + ALTER SERVER

          + DROP SERVER

          + CACHE INDEX

          + LOAD INDEX INTO CACHE

          + FLUSH

          + RESET
       (Bug #16062608)
       References: See also Bug #16484323.

     * Important Change; Replication: The version number reported by
       mysqlbinlog --version has been increased to 3.4. (Bug
       #15894381, Bug #67643)

     * Important Change; Replication: The lettercasing used for
       displaying UUIDs in global transaction identifiers was
       inconsistent. Now, all GTID values use lowercase, including
       those shown in the Retrieved_Gtid_Set and Executed_Gtid_Set
       columns from the output of SHOW SLAVE STATUS. (Bug #15869441)

     * Important Note; Replication: It was possible to replicate from
       a table to a same-named view using statement-based logging,
       while using row-based logging instead led to a failure on the
       slave. Now the target object type is checked prior to
       performing any DML, and an error is given if the target on the
       slave is not actually a table. This is true regardless of the
       binary logging format in use. (Bug #11752707, Bug #43975)

     * InnoDB: When parsing a delimited search string such as
       "abc-def" in a full-text search, InnoDB now uses the same word
       delimiters as MyISAM. (Bug #16419661)

     * InnoDB: This fix improves code readability by addressing
       naming inconsistencies for InnoDB PERFORMANCE_SCHEMA key
       declarations. (Bug #16414044)

     * InnoDB: This fix disables a condition for extra splitting of
       clustered index leaf pages, on compressed tables. Extra page
       splitting was only done to reserve space for future updates,
       so that future page splits could be avoided. (Bug #16401801)

     * InnoDB: For InnoDB tables, if a PRIMARY KEY on a VARCHAR
       column (or prefix) was empty, index page compression could
       fail. (Bug #16400920)

     * InnoDB: Status values in the INNODB_FT_CONFIG table would not
       update. The INNODB_FT_CONFIG is intended for internal
       configuration and should not be used for statistical
       information purposes. To avoid confusion, column values that
       are intended for internal use have been removed from the
       INNODB_FT_CONFIG table. This fix also removes the
       INNODB_FT_INSERTED table and other internal full text
       search-related tables that were unintentionally exposed. (Bug
       #16409494)

     * InnoDB: With innodb_api_enable_mdl=OFF, an ALTER TABLE
       operation on an InnoDB table that required a table copy could
       cause a server exit. (Bug #16287411)

     * InnoDB: Improper testing of compatibility between the
       referencing and referenced during ALTER TABLE ... ADD FOREIGN
       key could cause a server exit. (Bug #16330036)

     * InnoDB: Rollback did not include changes made to temporary
       tables by read-only transactions. (Bug #16310467)

     * InnoDB: The InnoDB page-splitting algorithm could recurse
       excessivly. (Bug #16345265)

     * InnoDB: For debug builds, InnoDB status exporting was subject
       to a race condition that could cause a server exit. (Bug
       #16292043)

     * InnoDB: When using ALTER TABLE to set an AUTO_INCREMENT column
       value to a user-specified value, InnoDB would set the
       AUTO_INCREMENT value to the user-specified value even when the
       AUTO_INCREMENT value is greater than the user-specified value.
       This fix ensures that the AUTO_INCREMENT value is set to the
       maximum of the user-specified value and
       MAX(auto_increment_column)+1, which is the expected behaviour.
       (Bug #16310273)

     * InnoDB: Importing a tablespace with the configuration file
       present would not import the data file. This problem would
       occur when all pages are not flushed from the buffer pool
       after a table is altered using the copy and rename approach.
       This fix ensures that all pages are flushed from the buffer
       pool when a table is altered using the copy and rename
       approach. (Bug #16318052)

     * InnoDB: The lock_validate function, which is only present in
       debug builds, acquired and released mutexes to avoid hogging
       them. This behavior introduced a window wherein changes to the
       hash table could occur while code traversed the same set of
       data. This fix updates lock_validate logic to collect all
       records for which locks must be validated, releases mutexes,
       and runs a loop to validate record locks. (Bug #16235056)

     * InnoDB: ALTER TABLE functions would perform a check to see if
       InnoDB is in read-only mode (srv_read_only_mode=true). If
       InnoDB was in read-only mode, the check would return a
       successful status and do nothing else. This fix replaces
       srv_read_only_mode check conditions with debug assertions.
       (Bug #16227539)

     * InnoDB: An improper call to abort() by InnoDB could result in
       a server exit. (Bug #16263506)

     * InnoDB: When the InnoDB buffer pool is almost filled with 4KB
       compressed pages, inserting into 16KB compact tables would
       cause 8KB pages_free to increase, which could potentially slow
       or stall inserts. (Bug #16223169)

     * InnoDB: An assertion failure would occur in heap->magic_n ==
       MEM_BLOCK_MAGIC_N due to a race condition that appeared when
       row_merge_read_clustered_index() returned an error. (Bug
       #16275237)

     * InnoDB: This fix removes an unnecessary debug assertion
       related to page_hash locks which only affects debug builds.
       The debug assertion is no longer valid and should have been
       removed when hash_lock array was introduced in MySQL 5.6. (Bug
       #16263167)

     * InnoDB: Without warning, InnoDB would silently set
       innodb-buffer-pool-instances to 1 if the buffer pool size is
       less than 1GB. For example, if innodb-buffer-pool-size is set
       to 200M and innodb-buffer-pool-instances is set to 4, InnoDB
       would silently set innodb-buffer-pool-instances to 1. This fix
       implements a warning message and new logic for
       innodb-buffer-pool-size and innodb-buffer-pool-instances. (Bug
       #16249500, Bug #61239)

     * InnoDB: When the primary key of a table includes a column
       prefix, and a full-text index is defined on the table, a
       full-text search resulted in an unnecessary warning being
       written to the error log. This fix suppresses the unnecessary
       warning. (Bug #16169411)

     * InnoDB: When InnoDB locking code was revised, a call to
       register lock waits was inadvertently removed. This fix adds
       the call back to the InnoDB locking code. (Bug #16208201)

     * InnoDB: A direct call to the trx_start_if_not_started_xa_low()
       function would cause a debug assertion. (Bug #16178995)

     * InnoDB: In the case of LOCK WAIT for an insert in a foreign
       key table, InnoDB could report a false dictionary-changed
       error and cause the insert to fail rather than being retried.
       (Bug #16174255)

     * InnoDB: In some cases, deadlock detection did not work,
       resulting in sessions hanging waiting for a lock-wait timeout.
       (Bug #16169638)

     * InnoDB: An in-place ALTER TABLE on an InnoDB table could fail
       to delete the statistics for the old primary key from the
       mysql.innodb_index_stats table. (Bug #16170451)

     * InnoDB: This fix updates InnoDB code in ha_innodb.cc and
       handler0alter.cc to use TABLE::key_info instead of both
       TABLE::key_info and TABLE_SHARE::key_info. (Bug #16215361)

     * InnoDB: Arithmetic underflow during page compression for
       CREATE TABLE on an InnoDB table could cause a server exit.
       (Bug #16089381)

     * InnoDB: LOCK_TIME would not be logged correctly in the slow
       query log. LOCK_TIME did not account for InnoDB row lock wait
       time. (Bug #16097753)

     * InnoDB: For debug builds, online ALTER TABLE operations for
       InnoDB tables could cause a server exit during table
       rebuilding. (Bug #16063835)

     * InnoDB: In some cases, the InnoDB purge coordinator did not
       use all available purge threads, resulting in suboptimal purge
       activity. (Bug #16037372)

     * InnoDB: ALTER TABLE for InnoDB tables was not fully atomic.
       (Bug #15989081)

     * InnoDB: This fix replaces most uses of UT_SORT_FUNCTION_BODY,
       an InnoDB recursive merge sort, with the std::sort() function
       from the C++ Standard Template Library (STL). The std::sort()
       function requires less memory and is faster due to in-line
       execution. (Bug #15920744)

     * InnoDB: This fix implements a 256-byte boundary for extending
       a VARCHAR column instead of 256-character boundary. This
       change allows for in-place extension of a VARCHAR column
       through an update of the data dictionary. (Bug #15863023)

     * InnoDB: This fix addresses unnecessary buffer pool lookups
       that would occur while freeing blob pages, and implements a
       debug status instrument, innodb_ahi_drop_lookups, for testing
       purposes. (Bug #15866009)

     * InnoDB: Due to a resource related bug, creating numerous
       tables that have a simple a full-text search index would cause
       excessive memory usage. This fix adds a global configuration
       parameter to limit the total memory size that full-text search
       indexes can use. If the global memory limit is reached by an
       index operation, a force sync is triggered. (Bug #14834698)

     * InnoDB: This fix modifies InnoDB code to ensure that unused
       thread handles are closed when the thread exits, instead of
       leaving thread handles open until shutdown of mysqld on
       Windows. (Bug #14762796)

     * InnoDB: This fix removes unnecessary overhead by removing
       table locking and disabling read view creation and MVCC when
       InnoDB is started in read-only mode (--innodb-read-only=true).
       (Bug #14729365)

     * InnoDB: An error at the filesystem level, such as too many
       open files, could cause an unhandled error during an ALTER
       TABLE operation. The error could be accompanied by Valgrind
       warnings, and by this assertion message:
Assertion `! is_set()' failed.
mysqld got signal 6 ;
       (Bug #14628410, Bug #16000909)

     * InnoDB: The INNODB_SYNC_ARRAY_SIZE variable was incorrectly
       allowed to be configured at runtime. As documented,
       INNODB_SYNC_ARRAY_SIZE must be configured when the MySQL
       instance is starting up, and cannot be changed afterward. This
       fix changes INNODB_SYNC_ARRAY_SIZE to a non-dynamic variable,
       as intended. (Bug #14629979)

     * InnoDB: The server could exit during an attempt by InnoDB to
       reorganize or compress a compressed secondary index page. (Bug
       #14606334)

     * InnoDB: A DML operation performed while a RENAME TABLE
       operation waits for pending I/O operations on the tablespace
       to complete would result in a deadlock. (Bug #14556349)

     * InnoDB: Attempting to unninstall the InnoDB memcached Plugin
       while the plugin is still installing caused the Mysql server
       to terminate. While the plugin deamon thread was still
       initializing, plugin variables were not yet set and the
       uninstall process could not cleanup resources. This fix adds a
       variable to indicate initialization status. If initialization
       is incomplete, the uninstall process will wait. (Bug
       #14279541)

     * InnoDB: If the value of innodb_force_recovery was less than 6,
       opening a corrupted table might loop forever if a corrupted
       page was read when calculating statistics for the table.
       Information about the corrupted page was written repeatedly to
       the error log, possibly causing a disk space issue. The fix
       causes the server to halt after a fixed number of failed
       attempts to read the page. To troubleshoot such a corruption
       issue, set innodb_force_recovery=6 and restart. (Bug
       #14147491, Bug #65469)

     * InnoDB: When printing out long semaphore wait diagnostics,
       sync_array_cell_print() ran into a segmentation violation
       (SEGV) caused by a race condition. This fix addresses the race
       condition by allowing the cell to be freed while it is being
       printed. (Bug #13997024)

     * InnoDB: Killing a query caused an InnoDB assertion failure
       when the same table (cursor) instance was used again. This is
       the result of a regression error introduced by the fix for
       Bug#14704286. The fix introduced a check to handle kill
       signals for long running queries but the cursor was not
       restored to the proper state. (Bug #68051, Bug #16088883)

     * InnoDB: On startup, InnoDB reported a message on 64-bit Linux
       and 64-bit Windows systems stating that the CPU does not
       support crc32 instructions. On Windows, InnoDB does not use
       crc32 instructions even if supported by the CPU. This fix
       revises the wording of the message and implements a check for
       availability of crc32 instructions. (Bug #68035, Bug
       #16075806)

     * InnoDB: The length of internally generated foreign key names
       was not checked. If internally generated foreign key names
       were over the 64 character limit, this resulted in invalid DDL
       from SHOW CREATE TABLE. This fix checks the length of
       internally generated foreign key names and reports an error
       message if the limit is exceeded. (Bug #44541, Bug #11753153)

     * InnoDB: This fix removes left-over prototype code for
       srv_parse_log_group_home_dirs, and related header comments.
       (Bug #68133, Bug #16198764)

     * InnoDB: Attempting to replace the default InnoDB FTS stopword
       list by creating an InnoDB table with the same structure as
       INFORMATION_SCHEMA.innodb_ft_default_stopword would result in
       an error. SHOW CREATE TABLE revealed that the new InnoDB table
       was created with CHARSET=utf8. The InnoDB FTS stopword table
       validity check only supported latin1. This fix extends the
       validity check for all supported character sets. (Bug #68450,
       Bug #16373868)

     * Partitioning: A query on a table partitioned by range and
       using TO_DAYS() as a partitioing function always included the
       first partition of the table when pruning. This happened
       regardless of the range employed in the BETWEEN clause of such
       a query. (Bug #15843818, Bug #49754)

     * Partitioning: Partition pruning is now enabled for tables
       using a storage engine that provides automatic partitioning,
       such as the NDB storage engine, but which are explicitly
       partitioned. Previously, pruning was disabled for all tables
       using such a storage engine, whether or not the tables had
       explicitly defined partitions.
       In addition, as part of this fix, explicit partition selection
       is now disabled for tables using a storage engine (such as
       NDB) that provides automatic partitioning. (Bug #14827952)
       References: See also Bug #14672885.

     * Partitioning: Execution of ALTER TABLE ... DROP PARTITION
       against a view caused the server to crash, rather than fail
       with an error as expected. (Bug #14653504)

     * Partitioning: A query result was not sorted if both DISTINCT
       and ORDER BY were used and the underlying table was
       partitioned. (Bug #14058167)

     * Partitioning: Inserting any number of rows into an ARCHIVE
       table that used more than 1000 partitions and then attempting
       to drop the table caused the MySQL Server to fail. (Bug
       #13819630, Bug #64580)

     * Replication; Linux; Microsoft Windows: Replication failed
       between a Linux master using lower_case_table_names set to 0
       and a Windows slave having lower_case_table_names set to 2,
       after a replicated table was opened on the slave; in addition,
       FLUSH TABLES was required afterwards to see which updates had
       actually been applied on the slave. This was because
       lower_case_table_names was checked only to see whether it was
       equal to 1 prior to forcing a conversion of replicated
       database object names to lower case for checking the table
       cache. Now in such cases, lower_case_table_names is checked to
       see whether it is set to a nonzero value. (Bug #16061982)

     * Replication: When using GTIDs and binary log auto-positioning,
       the master had to scan all binary logs whenever the slave
       reconnected (due to reasons such as I/O thread failure or a
       change of master) before it could send any events to slave.
       Now, the master starts from the oldest binary log that
       contains any GTID not found on the slave. (Bug #16340322, Bug
       #68386)

     * Replication: When the server version of the master was greater
       than or equal to 10, replication to a slave having a lower
       server version failed. (Bug #16237051, Bug #68187)

     * Replication: When replicating to a MySQL 5.6 master to an
       older slave, Error 1193 (ER_UNKNOWN_SYSTEM_VARIABLE) was
       logged with a message such as Unknown system variable
       'SERVER_UUID' on master, maybe it is a *VERY OLD MASTER*. This
       message has been improved to include more information, similar
       to this one: Unknown system variable 'SERVER_UUID' on master.
       A probable cause is that the variable is not supported on the
       master (version: 5.5.31), even though it is on the slave
       (version: 5.6.11). (Bug #16216404, Bug #68164)

     * Replication: A zero-length name for a user variable (such as
       @``) was incorrectly considered to be a sign of data or
       network corruption when reading from the binary log. (Bug
       #16200555, Bug #68135)

     * Replication: Running SHOW RELAYLOG EVENTS at a slave where no
       relay log file is present returned the following incorrect
       error message: "Error when executing command SHOW BINLOG
       EVENTS: Could not find target log." The error message text has
       been changed to: "Error when executing command SHOW RELAYLOG
       EVENTS: Could not find target log." (Bug #16191895)

     * Replication: When MTS is on and transactions are being
       applied, the slave coordinator would hang when encountering a
       checksum error on a transaction event. This was due to a
       deadlock situation in which the coordinator assumed a normal
       stop while a worker waited for the coordinator to dispatch
       more events. For debug builds, the problem appeared as an
       assertion failure, which was due to the coordinator not
       setting thd->is_error() when encountering an error. (Bug
       #16210351)

     * Replication: The print format specifier for the server_id was
       incorrectly defined as a signed 32-bit integer with a range of
       -2144783647 to 2144783648. This fix changes the server_id
       integer type to an unsigned 32-bit integer type, with a range
       of 0 to 4294967295, which is the documented range for the
       --server-id option. (Bug #16210894)

     * Replication: mysqlbinlog can connect to a remote server and
       read its binary logs. In MySQL 5.6 and later, this tool can
       also wait for the server to generate and send additional
       events, in practice behaving like a slave connecting to a
       master. In cases where the server sent a heartbeat,
       mysqlbinlog was unable to handle it properly. As a
       consequence, mysqlbinlog failed at this point, without reading
       any more events from the server. To fix this problem,
       mysqlbinlog now ignores any binary log events of type
       HEARTBEAT_LOG_EVENT that it receives. (Bug #16104206)

     * Replication: STOP SLAVE could cause a deadlock when issued
       concurrently with a statement such as SHOW STATUS that
       retrieved the values for one or more of the status variables
       Slave_retried_transactions, Slave_heartbeat_period,
       Slave_received_heartbeats, Slave_last_heartbeat, or
       Slave_running. (Bug #16088188, Bug #67545)
       References: See also Bug #16088114.

     * Replication: Using the --replicate-* options (see Replication
       Slave Options and Variables
       (http://dev.mysql.com/doc/refman/5.7/en/replication-options-sl
       ave.html)) could in some cases lead to a memory leak on the
       slave. (Bug #16056813, Bug #67983)

     * Replication: Backtick (`) characters were not always handled
       correctly in internally generated SQL statements, which could
       sometimes lead to errors on the slave. (Bug #16084594, Bug
       #68045)
       References: This bug is a regression of Bug #14548159, Bug
       #66550.

     * Replication: The session-level value for gtid_next was
       incorrectly reset on the slave for all rollbacks, which meant
       that GTIDs could be lost for multi-statement transactions,
       causing the slave to stop with an
       ER_GTID_NEXT_TYPE_UNDEFINED_GROUP error. Now this is done only
       when a complete transaction is being rolled back, or when
       autocommit is enabled. (Bug #16084206)

     * Replication: In order to provision or to restore a server
       using GTIDs, it is possible to set gtid_purged to a given GTID
       set listing the transactions that were imported. This
       operation requires that the global gtid_executed and
       gtid_purged server system variables are empty. (This is done
       in order to avoid the possibility of overriding
       server-generated GTIDs.)
       The error message GTID_PURGED can only be set when
       GTID_EXECUTED is empty that was raised when this requirement
       was not met could be confusing or misleading because it did
       not specify the scope of the affected variables. To prevent
       this from happening, error messages that refer to variables
       relating to GTIDs now specify the scope of any such variables
       when they do so. (Bug #16084426, Bug #68038)

   RPM Notes

     * It was not possible to upgrade a community RPM to a commercial
       RPM using rpm -uvh or yum localupdate. To deal with this, the
       RPM spec file has been updated in MySQL 5.5.31, which has the
       following consequences:

          + For a non-upgrade installation (no existing MySQL version
            installed), it possible to install MySQL using yum.

          + For upgrades, it is necessary to clean up any earlier
            MySQL installations. In effect, the update is performed
            by removing the old installations and installing the new
            one.
       Additional details follow.
       For a non-upgrade installation of MySQL 5.5.31, it is possible
       to install using yum:
shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm
       For upgrades to MySQL 5.5.31, the upgrade is performed by
       removing the old installation and installing the new one. To
       do this, use the following procedure:

         1. Remove the existing 5.5.X installation. OLDVERSION is the
            version to remove.
shell> rpm -e MySQL-server-OLDVERSION.glibc23.i386.rpm
            Repeat this step for all installed MySQL RPMs.

         2. Install the new version. NEWVERSION is the version to
            install.
shell> rpm -ivh MySQL-server-NEWVERSION.glibc23.i386.rpm
       Alternatively, the removal and installation can be done using
       yum:
shell> yum remove MySQL-server-OLDVERSION.glibc23.i386.rpm
shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm
       (Bug #16445097, Bug #16445125)

   Functionality Added or Changed

     * MySQL no longer uses the default OpenSSL compression. (Bug
       #16235681)

   Bugs Fixed

     * InnoDB; Performance: Performance was improved for operations
       on tables with many rows that were deleted but not yet purged
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_pur
       ge). The speedup applies mainly to workloads that perform bulk
       deletes, or updates to the primary key
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_pri
       mary_key) columns, and where the system is busy enough to
       experience purge lag
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_pur
       ge_lag). (Bug #16138582, Bug #68069)

     * InnoDB; Performance: The DROP TABLE statement for a table
       using compression
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_com
       pression) could be slower than necessary, causing a stall for
       several seconds. MySQL was unnecessarily decompressing pages
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_pag
       e) in the buffer pool
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_buf
       fer_pool) related to the table as part of the DROP operation.
       (Bug #16067973)

     * Incompatible Change; Partitioning: Changes in the KEY
       partitioning hashing functions used with numeric, date and
       time, ENUM, and SET columns in MySQL 5.5 makes tables using
       partitioning or subpartitioning by KEY on any of the affected
       column types and created on a MySQL 5.5 or later server
       incompatible with a MySQL 5.1 server. This is because the
       partition IDs as calculated by a MySQL 5.5 or later server
       almost certainly differ from those calculated by a MySQL 5.1
       server for the same table definition and data as a result of
       the changes in these functions.
       The principal changes in the KEY partitioning implementation
       in MySQL 5.5 resulting in this issue were as follows: 1. The
       hash function used for numeric and date and time columns
       changed from binary to character-based. 2. The base used for
       hashing of ENUM and SET columns changed from latin1 ci
       characters to binary.
       The fix involves adding the capability in MySQL 5.5 and later
       to choose which type of hashing to use for KEY partitioning,
       which is implemented with a new ALGORITHM extension to the
       PARTITION BY KEY option for CREATE TABLE and ALTER TABLE.
       Specifying PARTITION BY KEY ALGORITHM=1 ([columns]) causes the
       server to use the hashing functions as implemented in MySQL
       5.1; using ALGORITHM=2 causes the server to use the hashing
       functions from MySQL 5.5 and later. ALGORITHM=2 is the
       default. Using the appropriate value for ALGORITHM, you can
       perform any of the following tasks:

          + Create KEY partitioned tables in MySQL 5.5 and later that
            are compatible with MySQL 5.1, using CREATE TABLE ...
            PARTITION BY KEY ALGORITHM=1 (...).

          + Downgrade KEY partitioned tables that were created in
            MySQL 5.5 or later to become compatible with MySQL 5.1,
            using ALTER TABLE ... PARTITION BY KEY ALGORITHM=1 (...).

          + Upgrade KEY partitioned tables originally created in
            MySQL 5.1 to use hashing as in MySQL 5.5 and later, using
            ALTER TABLE ... PARTITION BY KEY ALGORITHM=2 (...).
            Important: After such tables are upgraded, they cannot be
            used any longer with MySQL 5.1 unless they are first
            downgraded again using ALTER TABLE ... PARTITION BY KEY
            ALGORITHM=1 (...) on a MySQL server supporting this
            option.
       This syntax is not backward compatible, and causes errors in
       older versions of the MySQL server. When generating CREATE
       TABLE ... PARTITION BY KEY statements, mysqldump brackets any
       occurrence of ALGORITHM=1 or ALGORITHM=2 in conditional
       comments such that it is ignored by a MySQL server whose
       version is not at least 5.5.31. An additional consideration
       for upgrades is that MySQL 5.6 servers prior to MySQL 5.6.11
       do not ignore the ALGORITHM option in such statements when
       generated by a MySQL 5.5 server, due to the that the
       conditional comments refer to version 5.5.31; in this case,
       you must edit the dump manually and remove or comment out the
       option wherever it occurs before attempting to load it into a
       MySQL 5.6.10 or earlier MySQL 5.6 server. This is not an issue
       for dumps generated by MySQL 5.6.11 or later version of
       mysqldump, where the version used in such comments is 5.6.11.
       For more information, see ALTER TABLE Partition Operations
(http://dev.mysql.com/doc/refman/5.5/en/alter-table-partition-
       operations.html).
       As part of this fix, a spurious assertion by InnoDB that a
       deleted row had previously been read, causing the server to
       assert on delete of a row that the row was in the wrong
       partition, was also removed. (Bug #14521864, Bug #66462, Bug
       #16093958, Bug #16274455)
       References: See also Bug #11759782.

     * Important Note; Replication: It was possible to replicate from
       a table to a same-named view using statement-based logging,
       while using row-based logging instead led to a failure on the
       slave. Now the target object type is checked prior to
       performing any DML, and an error is given if the target on the
       slave is not actually a table. This is true regardless of the
       binary logging format in use. (Bug #11752707, Bug #43975)

     * InnoDB: For InnoDB tables, if a PRIMARY KEY on a VARCHAR
       column (or prefix) was empty, index page compression could
       fail. (Bug #16400920)

     * InnoDB: For debug builds, InnoDB status exporting was subject
       to a race condition that could cause a server exit. (Bug
       #16292043)

     * InnoDB: Internal read operations could be misclassified as
       synchronous when they were actually asynchronous. When the I/O
       requests returned sooner than expected, threads could be
       scheduled inefficiently. This issue mainly affected read-ahead
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_rea
       d_ahead) requests, and thus had relatively little impact on
       I/O performed by user queries. (Bug #16249505, Bug #68197)

     * InnoDB: An improper call to abort() by InnoDB could result in
       a server exit. (Bug #16263506)

     * InnoDB: If the MySQL server halted at a precise moment when a
       purge operation was being applied from the change buffer
(http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_cha
       nge_buffer), the operation could be incorrectly performed
       again during the next restart. A workaround was to set the
       configuration option innodb_change_buffering=changes, to turn
       off change buffering for purge operations. (Bug #16183892, Bug
       #14636528)

     * InnoDB: Arithmetic underflow during page compression for
       CREATE TABLE on an InnoDB table could cause a server exit.
       (Bug #16089381)

     * InnoDB: If the server was started with the skip-innodb option,
       or InnoDB otherwise failed to start, query any of these
       Information Schema tables would cause a severe error:

          + INNODB_BUFFER_PAGE

          + INNODB_BUFFER_PAGE_LRU

          + INNODB_BUFFER_POOL_STATS
       (Bug #14144290)

     * InnoDB: When printing out long semaphore wait diagnostics,
       sync_array_cell_print() ran into a segmentation violation
       (SEGV) caused by a race condition. This fix addresses the race
       condition by allowing the cell to be freed while it is being
       printed. (Bug #13997024)

     * InnoDB: Killing a query caused an InnoDB assertion failure
       when the same table (cursor) instance was used again. This is
       the result of a regression error introduced by the fix for
       Bug#14704286. The fix introduced a check to handle kill
       signals for long running queries but the cursor was not
       restored to the proper state. (Bug #68051, Bug #16088883)

     * InnoDB: The length of internally generated foreign key names
       was not checked. If internally generated foreign key names
       were over the 64 character limit, this resulted in invalid DDL
       from SHOW CREATE TABLE. This fix checks the length of
       internally generated foreign key names and reports an error
       message if the limit is exceeded. (Bug #44541, Bug #11753153)

     * Partitioning: A query on a table partitioned by range and
       using TO_DAYS() as a partitioing function always included the
       first partition of the table when pruning. This happened
       regardless of the range employed in the BETWEEN clause of such
       a query. (Bug #15843818, Bug #49754)

     * Partitioning: Execution of ALTER TABLE ... DROP PARTITION
       against a view caused the server to crash, rather than fail
       with an error as expected. (Bug #14653504)

     * Replication: A zero-length name for a user variable (such as
       @``) was incorrectly considered to be a sign of data or
       network corruption when reading from the binary log. (Bug
       #16200555, Bug #68135)

     * Replication: Using the --replicate-* options (see Replication
       Slave Options and Variables
(http://dev.mysql.com/doc/refman/5.5/en/replication-options-sl
       ave.html)) could in some cases lead to a memory leak on the
       slave. (Bug #16056813, Bug #67983)

     * Replication: Backtick (`) characters were not always handled
       correctly in internally generated SQL statements, which could
       sometimes lead to errors on the slave. (Bug #16084594, Bug
       #68045)
       References: This bug is a regression of Bug #14548159, Bug
       #66550.

     * Replication: It was possible immediately after detecting an
       EOF in the dump thread read event loop, and before deciding
       whether to change to a new binary log file, for new events to
       be written to the binary log concurrently with rotating the
       log. If log rotation occurred during this window, any events
       that also occurred at that time were dropped, resulting in
       loss of data. Now in such cases, steps are taken to make sure
       that no more events remain before allowing the log rotation to
       take place. (Bug #13545447, Bug #67929)
       References: See also Bug #16016886.

     * SHOW ENGINE PERFORMANCE_SCHEMA STATUS could report incorrect
       memory-allocation values when the correct values exceeded 4GB.
       (Bug #16414644)

     * A long database name in a GRANT statement could cause the
       server to exit. (Bug #16372927)

     * On Linux, a race condition involving epoll() could cause the
       thread pool plugin to miss events. This was most likely on
       systems with greater than 16 cores. (Bug #16367483)

     * The server could exit if a prepared statement attempted to
       create a table using the name of an existing view while an SQL
       handler was opened. (Bug #16385711)

     * Incorrect results were returned if a query contained a
       subquery in an IN clause which contained an XOR operation in
       the WHERE clause. (Bug #16311231)

     * For upgrade operations, RPM packages produced unnecessary
       errors about being unable to access .err files. (Bug
       #16235828)

     * Invocation of the range optimizer for a NULL select caused the
       server to exit. (Bug #16192219)

     * yaSSL did not perform proper padding checks, but instead
       examined only the last byte of plaintext and used it to
       determine how many bytes to remove. (Bug #16218104)

     * With the thread pool plugin enabled, large numbers of
       connections could lead to a Valgrind panic or failure of
       clients to be able to connect. (Bug #16088658, Bug #16196591)

     * The initial test database contained a dummy.bak file that
       prevented DROP DATABASE from working. This file is no longer
       included. Also, a db.opt file is now included that contains
       these lines:
default-character-set=latin1
default-collation=latin1_swedish_ci
       (Bug #16062056)

     * Setting a system variable to DEFAULT could cause the server to
       exit. (Bug #16044655)

     * Issuing a PREPARE statement using certain combinations of
       stored functions and user variables caused the server to exit.
       (Bug #16056537)

     * Contention in the thread pool during kill processing could
       lead to a Valgrind panic. (Bug #15921866)

     * When a client program loses the connection to the MySQL server
       or if the server begins a shutdown after the client has
       executed mysql_stmt_prepare(), the next mysql_stmt_prepare()
       returns an error (as expected) but subsequent
       mysql_stmt_execute() calls crash the client. (Bug #14553380)

     * SHOW COLUMNS on a view defined as a UNION of Geometry columns
       could cause the server to exit. (Bug #14362617)

     * A LIKE pattern with too many '%' wildcards could cause a
       segmentation fault. (Bug #14303860)

     * SET var_name = VALUES(col_name) could cause the server to
       exit. This syntax is now prohibited because in SET context
       there is no column name and the statement returns
       ER_BAD_FIELD_ERROR. (Bug #14211565)

     * The COM_CHANGE_USER command in the client/server protocol did
       not properly use the character set number in the command
       packet, leading to incorrect character set conversion of other
       values in the packet. (Bug #14163155)

     * Subqueries with OUTER JOIN could return incorrect results if
       the subquery referred to a column from another SELECT. (Bug
       #13068506)

     * On Microsoft Windows, the MSI package would now allow a
       license switch (community to or from the commercial edition)
       when the switched MySQL Server versions were identical. (Bug
       #13071597)

     * mysql_install_db did not escape '_' in the host name for
       statements written to the grant tables. (Bug #11746817)

     * An out-of-memory condition could occur while handling an
       out-of-memory error, leading to recursion in error handling.
       (Bug #49514, Bug #11757464)

     * The optimizer used loose index scan for some queries for which
       this access method is inapplicable. (Bug #42785, Bug
       #11751794)

     * If a dump file contained a view with one character set and
       collation defined on a view with a different character set and
       collation, attempts to restore the dump file failed with an
       "illegal mix of collations" error. (Bug #65382, Bug #14117025)

     * The REPLACE() function produced incorrect results when a user
       variable was supplied as an argument and the operation was
       performed on multiple rows. (Bug #49271, Bug #11757250)

     * UNION ALL on BLOB columns could produce incorrect results.
       (Bug #50136, Bug #11758009)

     * View access in low memory conditions could raise a debugging
       assertion. (Bug #39307, Bug #11749556)

     * Setting max_connections to a value less than the current
       number of open connections caused the server to exit. (Bug
       #44100, Bug #11752803)

     * Incorrect metadata could be produced for columns returned from
       some views. (Bug #65379, Bug #14096619)

     * For debug builds, some queries with SELECT ... FROM DUAL
       nested subqueries raised an assertion. (Bug #60305, Bug
       #11827369)

     * If the server was started without a --datadir option, SHOW
       VARIABLES could show an empty value for the datadir system
       variable. (Bug #60995, Bug #12546953)

     * CMake did not check whether the system zlib had certain
       functions required for MySQL, resulting in build errors. Now
       it checks and falls back to the bundled zlib if the functions
       are missing. (Bug #65856, Bug #14300733)

   Functionality Added or Changed

     * MySQL no longer uses the default OpenSSL compression. (Bug
       #16235681)

   Bugs Fixed

     * InnoDB; Performance: The DROP TABLE statement for a table
       using compression
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_com
       pression) could be slower than necessary, causing a stall for
       several seconds. MySQL was unnecessarily decompressing pages
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_pag
       e) in the buffer pool
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_buf
       fer_pool) related to the table as part of the DROP operation.
       (Bug #16067973)

     * Important Note; Replication: It was possible to replicate from
       a table to a same-named view using statement-based logging,
       while using row-based logging instead led to a failure on the
       slave. Now the target object type is checked prior to
       performing any DML, and an error is given if the target on the
       slave is not actually a table. This is true regardless of the
       binary logging format in use. (Bug #11752707, Bug #43975)

     * InnoDB: This fix makes MySQL more responsive to KILL QUERY
       statements when the query is accessing an InnoDB table. (Bug
       #14704286)

     * InnoDB: When printing out long semaphore wait diagnostics,
       sync_array_cell_print() ran into a segmentation violation
       (SEGV) caused by a race condition. This fix addresses the race
       condition by allowing the cell to be freed while it is being
       printed. (Bug #13997024)

     * InnoDB: Killing a query caused an InnoDB assertion failure
       when the same table (cursor) instance was used again. This is
       the result of a regression error introduced by the fix for
       Bug#14704286. The fix introduced a check to handle kill
       signals for long running queries but the cursor was not
       restored to the proper state. (Bug #68051, Bug #16088883)

     * InnoDB: The length of internally generated foreign key names
       was not checked. If internally generated foreign key names
       were over the 64 character limit, this resulted in invalid DDL
       from SHOW CREATE TABLE. This fix checks the length of
       internally generated foreign key names and reports an error
       message if the limit is exceeded. (Bug #44541, Bug #11753153)

     * Partitioning: A query on a table partitioned by range and
       using TO_DAYS() as a partitioing function always included the
       first partition of the table when pruning. This happened
       regardless of the range employed in the BETWEEN clause of such
       a query. (Bug #15843818, Bug #49754)

     * Replication: A zero-length name for a user variable (such as
       @``) was incorrectly considered to be a sign of data or
       network corruption when reading from the binary log. (Bug
       #16200555, Bug #68135)

     * Replication: Backtick (`) characters were not always handled
       correctly in internally generated SQL statements, which could
       sometimes lead to errors on the slave. (Bug #16084594, Bug
       #68045)
       References: This bug is a regression of Bug #14548159, Bug
       #66550.

     * A long database name in a GRANT statement could cause the
       server to exit. (Bug #16372927)

     * Incorrect results were returned if a query contained a
       subquery in an IN clause which contained an XOR operation in
       the WHERE clause. (Bug #16311231)

     * Invocation of the range optimizer for a NULL select caused the
       server to exit. (Bug #16192219)

     * yaSSL did not perform proper padding checks, but instead
       examined only the last byte of plaintext and used it to
       determine how many bytes to remove. (Bug #16218104)

     * SHOW COLUMNS on a view defined as a UNION of Geometry columns
       could cause the server to exit. (Bug #14362617)

     * A LIKE pattern with too many '%' wildcards could cause a
       segmentation fault. (Bug #14303860)

     * SET var_name = VALUES(col_name) could cause the server to
       exit. This syntax is now prohibited because in SET context
       there is no column name and the statement returns
       ER_BAD_FIELD_ERROR. (Bug #14211565)

     * The COM_CHANGE_USER command in the client/server protocol did
       not properly use the character set number in the command
       packet, leading to incorrect character set conversion of other
       values in the packet. (Bug #14163155)

     * Subqueries with OUTER JOIN could return incorrect results if
       the subquery referred to a column from another SELECT. (Bug
       #13068506)

     * Field_geom::reset() failed to reset its base Field_blob. The
       range optimizer used the uninitialized field during
       optimization and execution, causing the server to exit. (Bug
       #11908153)

     * mysql_install_db did not escape '_' in the host name for
       statements written to the grant tables. (Bug #11746817)

     * PARTITION BY KEY on a utf32 ENUM column raised a debugging
       assertion. (Bug #52121, Bug #11759782)

     * The optimizer used loose index scan for some queries for which
       this access method is inapplicable. (Bug #42785, Bug
       #11751794)

     * If a dump file contained a view with one character set and
       collation defined on a view with a different character set and
       collation, attempts to restore the dump file failed with an
       "illegal mix of collations" error. (Bug #65382, Bug #14117025)

     * The REPLACE() function produced incorrect results when a user
       variable was supplied as an argument and the operation was
       performed on multiple rows. (Bug #49271, Bug #11757250)

     * UNION ALL on BLOB columns could produce incorrect results.
       (Bug #50136, Bug #11758009)

     * View access in low memory conditions could raise a debugging
       assertion. (Bug #39307, Bug #11749556)

     * Setting max_connections to a value less than the current
       number of open connections caused the server to exit. (Bug
       #44100, Bug #11752803)

     * Incorrect metadata could be produced for columns returned from
       some views. (Bug #65379, Bug #14096619)

     * For debug builds, some queries with SELECT ... FROM DUAL
       nested subqueries raised an assertion. (Bug #60305, Bug
       #11827369)

     * Adjusted MySQL configuration to account for change in Automake
       1.12 that produced sql_yacc.hh rather than sql_yacc.h as
       expected by sql/Makefile.am. (Bug #67177, Bug #15967374)

   RPM Notes

     * It was not possible to upgrade a community RPM to a commercial
       RPM using rpm -uvh or yum localupdate. To deal with this, the
       RPM spec file has been updated in MySQL 5.6.11, which has the
       following consequences:

          + For a non-upgrade installation (no existing MySQL version
            installed), it possible to install MySQL using yum.

          + For upgrades, it is necessary to clean up any earlier
            MySQL installations. In effect, the update is performed
            by removing the old installations and installing the new
            one.

       Additional details follow.
       For a non-upgrade installation of MySQL 5.6.11, it is possible
       to install using yum:
       shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm
       For upgrades to MySQL 5.6.11, the upgrade is performed by
       removing the old installation and installing the new one. To
       do this, use the following procedure:

         1. Remove the existing 5.6.X installation. OLDVERSION is the
            version to remove.
            shell> rpm -e MySQL-server-OLDVERSION.glibc23.i386.rpm
            Repeat this step for all installed MySQL RPMs.

         2. Install the new version. NEWVERSION is the version to
            install.
            shell> rpm -ivh MySQL-server-NEWVERSION.glibc23.i386.rpm

       Alternatively, the removal and installation can be done using
       yum:
       shell> yum remove MySQL-server-OLDVERSION.glibc23.i386.rpm
       shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm
       (Bug #16445097, Bug #16445125, Bug #16587285)

   Functionality Added or Changed

     * Replication: The functions GTID_SUBTRACT() and GTID_SUBSET()
       were formerly available in libmysqld only when it was built
       with replication support. Now these functions are always
       available when using this library, regardless of how it was
       built.

     * MySQL no longer uses the default OpenSSL compression. (Bug
       #16235681)

     * There is now a distinct error code
       (ER_MUST_CHANGE_PASSWORD_LOGIN) for the error sent by the
       server to a client authenticating with an expired password.
       (Bug #16102943)

     * mysql_config_editor now supports --port and --socket options
       for specifying TCP/IP port number and Unix socket file name.
       (Bug #15851247)

     * mysqlcheck has a new --skip-database option. The option value
       is the name of a database (case sensitive) for which checks
       should be skipped.
       mysql_upgrade uses this option to upgrade the system tables in
       the mysql database before tables in other databases: It
       upgrade the mysql database, then all databases except the
       mysql database. This avoids problems that can occur if user
       tables are upgraded before the system tables. (Bug #14697538)

     * The only supported value for the innodb_mirrored_log_groups
       system variable is 1, so this variable is now deprecated.
       Setting it to 1 at startup results in a warning. Setting it to
       a value other than 1 at startup results in an error and the
       server exits. This variable will be removed in a future
       release.

   Bugs Fixed

     * InnoDB; Performance: Switching the MySQL table used by the
       InnoDB memcached interface
       (http://dev.mysql.com/doc/refman/5.6/en/innodb-memcached.html)
       (using the @@ notation), was made more efficient, by reading
       cached information about the cache policy to use for each
       table. This optimization lets you frequently switch between
       tables during a session that uses the memcached interface,
       without incurring I/O overhead from examining table metadata
       each time. (Bug #16206654)

     * InnoDB; Performance: Performance was improved for operations
       on tables with many rows that were deleted but not yet purged
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_pur
       ge). The speedup applies mainly to workloads that perform bulk
       deletes, or updates to the primary key
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_pri
       mary_key) columns, and where the system is busy enough to
       experience purge lag
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_pur
       ge_lag). (Bug #16138582, Bug #68069)

     * InnoDB; Performance: The DROP TABLE statement for a table
       using compression
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_com
       pression) could be slower than necessary, causing a stall for
       several seconds. MySQL was unnecessarily decompressing pages
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_pag
       e) in the buffer pool
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_buf
       fer_pool) related to the table as part of the DROP operation.
       (Bug #16067973)

     * InnoDB; Performance: The I/O routines used when the AIO
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_aio
       ) subsystem were made more efficient, to merge consecutive I/O
       requests into a single operation. This fix solves a
       performance issue introduced during the 5.6 development cycle.
       (Bug #16043841, Bug #67973)

     * Incompatible Change; Partitioning: Changes in the KEY
       partitioning hashing functions used with numeric, date and
       time, ENUM, and SET columns in MySQL 5.5 makes tables using
       partitioning or subpartitioning by KEY on any of the affected
       column types and created on a MySQL 5.5 or later server
       incompatible with a MySQL 5.1 server. This is because the
       partition IDs as calculated by a MySQL 5.5 or later server
       almost certainly differ from those calculated by a MySQL 5.1
       server for the same table definition and data as a result of
       the changes in these functions.
       The principal changes in the KEY partitioning implementation
       in MySQL 5.5 resulting in this issue were as follows: 1. The
       hash function used for numeric and date and time columns
       changed from binary to character-based. 2. The base used for
       hashing of ENUM and SET columns changed from latin1 ci
       characters to binary.
       The fix involves adding the capability in MySQL 5.5 and later
       to choose which type of hashing to use for KEY partitioning,
       which is implemented with a new ALGORITHM extension to the
       PARTITION BY KEY option for CREATE TABLE and ALTER TABLE.
       Specifying PARTITION BY KEY ALGORITHM=1 ([columns]) causes the
       server to use the hashing functions as implemented in MySQL
       5.1; using ALGORITHM=2 causes the server to use the hashing
       functions from MySQL 5.5 and later. ALGORITHM=2 is the
       default. Using the appropriate value for ALGORITHM, you can
       perform any of the following tasks:

          + Create KEY partitioned tables in MySQL 5.5 and later that
            are compatible with MySQL 5.1, using CREATE TABLE ...
            PARTITION BY KEY ALGORITHM=1 (...).

          + Downgrade KEY partitioned tables that were created in
            MySQL 5.5 or later to become compatible with MySQL 5.1,
            using ALTER TABLE ... PARTITION BY KEY ALGORITHM=1 (...).

          + Upgrade KEY partitioned tables originally created in
            MySQL 5.1 to use hashing as in MySQL 5.5 and later, using
            ALTER TABLE ... PARTITION BY KEY ALGORITHM=2 (...).
            Important: After such tables are upgraded, they cannot be
            used any longer with MySQL 5.1 unless they are first
            downgraded again using ALTER TABLE ... PARTITION BY KEY
            ALGORITHM=1 (...) on a MySQL server supporting this
            option.

       This syntax is not backward compatible, and causes errors in
       older versions of the MySQL server. When generating CREATE
       TABLE ... PARTITION BY KEY statements, mysqldump brackets any
       occurrence of ALGORITHM=1 or ALGORITHM=2 in conditional
       comments such that it is ignored by a MySQL server whose
       version is not at least 5.5.31. An additional consideration
       for upgrades is that MySQL 5.6 servers prior to MySQL 5.6.11
       do not ignore the ALGORITHM option in such statements when
       generated by a MySQL 5.5 server, due to the that the
       conditional comments refer to version 5.5.31; in this case,
       you must edit the dump manually and remove or comment out the
       option wherever it occurs before attempting to load it into a
       MySQL 5.6.10 or earlier MySQL 5.6 server. This is not an issue
       for dumps generated by MySQL 5.6.11 or later version of
       mysqldump, where the version used in such comments is 5.6.11.
       For more information, see ALTER TABLE Partition Operations
       (http://dev.mysql.com/doc/refman/5.6/en/alter-table-partition-
       operations.html).
       As part of this fix, a spurious assertion by InnoDB that a
       deleted row had previously been read, causing the server to
       assert on delete of a row that the row was in the wrong
       partition, was also removed. (Bug #14521864, Bug #66462, Bug
       #16093958, Bug #16274455)
       References: See also Bug #11759782.

     * Replication; Important Change: Executing a statement that
       performs an implicit commit but whose changes are not logged
       when gtid_next is set to any value other than AUTOMATIC is not
       permitted. Now in such cases, the statement fails with an
       error. This includes the statements in the following list:

          + CHANGE MASTER TO

          + START SLAVE

          + STOP SLAVE

          + REPAIR TABLE

          + OPTIMIZE TABLE

          + ANALYZE TABLE

          + CHECK TABLE

          + CREATE SERVER

          + ALTER SERVER

          + DROP SERVER

          + CACHE INDEX

          + LOAD INDEX INTO CACHE

          + FLUSH

          + RESET
       (Bug #16062608)
       References: See also Bug #16484323.

     * Replication; Important Change: The version number reported by
       mysqlbinlog --version has been increased to 3.4. (Bug
       #15894381, Bug #67643)

     * Important Note; Replication: It was possible to replicate from
       a table to a same-named view using statement-based logging,
       while using row-based logging instead led to a failure on the
       slave. Now the target object type is checked prior to
       performing any DML, and an error is given if the target on the
       slave is not actually a table. This is true regardless of the
       binary logging format in use. (Bug #11752707, Bug #43975)

     * InnoDB: When ADD PRIMARY KEY columns are reordered in an ALTER
       TABLE statement (for example: ALTER TABLE t1 ADD PRIMARY
       KEY(a,b), CHANGE a a INT AFTER b), the log apply for UPDATE
       operations would fail to find rows. (Bug #16586355)

     * InnoDB: ALTER TABLE operations on InnoDB tables that added a
       PRIMARY KEY using a column prefix could produce an incorrect
       result. (Bug #16544336)

     * InnoDB: For ALTER TABLE operations on InnoDB tables that
       required a table-copying operation, other transactions on the
       table might fail during the copy. However, if such a
       transaction issued a partial rollback, the rollback was
       treated as a full rollback. (Bug #16544143)

     * InnoDB: When parsing a delimited search string such as
       "abc-def" in a full-text search, InnoDB now uses the same word
       delimiters as MyISAM. (Bug #16419661)

     * InnoDB: This fix improves code readability by addressing
       naming inconsistencies for InnoDB PERFORMANCE_SCHEMA key
       declarations. (Bug #16414044)

     * InnoDB: This fix disables a condition for extra splitting of
       clustered index leaf pages, on compressed tables. Extra page
       splitting was only done to reserve space for future updates,
       so that future page splits could be avoided. (Bug #16401801)

     * InnoDB: For InnoDB tables, if a PRIMARY KEY on a VARCHAR
       column (or prefix) was empty, index page compression could
       fail. (Bug #16400920)

     * InnoDB: Status values in the INNODB_FT_CONFIG table would not
       update. The INNODB_FT_CONFIG is intended for internal
       configuration and should not be used for statistical
       information purposes. To avoid confusion, column values that
       are intended for internal use have been removed from the
       INNODB_FT_CONFIG table. This fix also removes the
       INNODB_FT_INSERTED table and other internal full text
       search-related tables that were unintentionally exposed. (Bug
       #16409494)

     * InnoDB: With innodb_api_enable_mdl=OFF, an ALTER TABLE
       operation on an InnoDB table that required a table copy could
       cause a server exit. (Bug #16287411)

     * InnoDB: Improper testing of compatibility between the referencing
       table and referenced table during ALTER TABLE ... ADD FOREIGN key
       could cause a server exit. (Bug #16330036)


     * InnoDB: Rollback did not include changes made to temporary
       tables by read-only transactions. (Bug #16310467)

     * InnoDB: The InnoDB page-splitting algorithm could recurse
       excessivly. (Bug #16345265)

     * InnoDB: For debug builds, InnoDB status exporting was subject
       to a race condition that could cause a server exit. (Bug
       #16292043)

     * InnoDB: When using ALTER TABLE to set an AUTO_INCREMENT column
       value to a user-specified value, InnoDB would set the
       AUTO_INCREMENT value to the user-specified value even when the
       AUTO_INCREMENT value is greater than the user-specified value.
       This fix ensures that the AUTO_INCREMENT value is set to the
       maximum of the user-specified value and
       MAX(auto_increment_column)+1, which is the expected behaviour.
       (Bug #16310273)

     * InnoDB: Importing a tablespace with the configuration file
       present would not import the data file. This problem would
       occur when all pages are not flushed from the buffer pool
       after a table is altered using the copy and rename approach.
       This fix ensures that all pages are flushed from the buffer
       pool when a table is altered using the copy and rename
       approach. (Bug #16318052)

     * InnoDB: RENAME TABLE would result in a hang due to a MySQL
       mutex acquisition deadlock. (Bug #16305265)

     * InnoDB: Internal read operations could be misclassified as
       synchronous when they were actually asynchronous. When the I/O
       requests returned sooner than expected, threads could be
       scheduled inefficiently. This issue mainly affected read-ahead
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_rea
       d_ahead) requests, and thus had relatively little impact on
       I/O performed by user queries. (Bug #16249505, Bug #68197)

     * InnoDB: The lock_validate function, which is only present in
       debug builds, acquired and released mutexes to avoid hogging
       them. This behavior introduced a window wherein changes to the
       hash table could occur while code traversed the same set of
       data. This fix updates lock_validate logic to collect all
       records for which locks must be validated, releases mutexes,
       and runs a loop to validate record locks. (Bug #16235056)

     * InnoDB: ALTER TABLE functions would perform a check to see if
       InnoDB is in read-only mode (srv_read_only_mode=true). If
       InnoDB was in read-only mode, the check would return a
       successful status and do nothing else. This fix replaces
       srv_read_only_mode check conditions with debug assertions.
       (Bug #16227539)

     * InnoDB: An improper call to abort() by InnoDB could result in
       a server exit. (Bug #16263506)

     * InnoDB: When the InnoDB buffer pool is almost filled with 4KB
       compressed pages, inserting into 16KB compact tables would
       cause 8KB pages_free to increase, which could potentially slow
       or stall inserts. (Bug #16223169)

     * InnoDB: An assertion failure would occur in heap->magic_n ==
       MEM_BLOCK_MAGIC_N due to a race condition that appeared when
       row_merge_read_clustered_index() returned an error. (Bug
       #16275237)

     * InnoDB: This fix removes an unnecessary debug assertion
       related to page_hash locks which only affects debug builds.
       The debug assertion is no longer valid and should have been
       removed when hash_lock array was introduced in MySQL 5.6. (Bug
       #16263167)

     * InnoDB: The InnoDB memcached plugin could encounter a serious
       error under a heavy load, such as produced by benchmark runs.
       (Bug #16182660, Bug #68096)

     * InnoDB: If the MySQL server halted at a precise moment when a
       purge operation was being applied from the change buffer
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_cha
       nge_buffer), the operation could be incorrectly performed
       again during the next restart. A workaround was to set the
       configuration option innodb_change_buffering=changes, to turn
       off change buffering for purge operations. (Bug #16183892, Bug
       #14636528)

     * InnoDB: When InnoDB locking code was revised, a call to
       register lock waits was inadvertently removed. This fix adds
       the call back to the InnoDB locking code. (Bug #16208201)

     * InnoDB: A direct call to the trx_start_if_not_started_xa_low()
       function would cause a debug assertion. (Bug #16178995)

     * InnoDB: In the case of LOCK WAIT for an insert in a foreign
       key table, InnoDB could report a false dictionary-changed
       error and cause the insert to fail rather than being retried.
       (Bug #16174255)

     * InnoDB: In some cases, deadlock detection did not work,
       resulting in sessions hanging waiting for a lock-wait timeout.
       (Bug #16169638)

     * InnoDB: An in-place ALTER TABLE on an InnoDB table could fail
       to delete the statistics for the old primary key from the
       mysql.innodb_index_stats table. (Bug #16170451)

     * InnoDB: This fix updates InnoDB code in ha_innodb.cc and
       handler0alter.cc to use TABLE::key_info instead of both
       TABLE::key_info and TABLE_SHARE::key_info. (Bug #16215361)

     * InnoDB: Arithmetic underflow during page compression for
       CREATE TABLE on an InnoDB table could cause a server exit.
       (Bug #16089381)

     * InnoDB: For debug builds, online ALTER TABLE operations for
       InnoDB tables could cause a server exit during table
       rebuilding. (Bug #16063835)

     * InnoDB: In some cases, the InnoDB purge coordinator did not
       use all available purge threads, resulting in suboptimal purge
       activity. (Bug #16037372)

     * InnoDB: On systems that cannot handle unaligned memory access,
       depending on the stack frame alignment, a SIGBUS error could
       occur during startup. This issue was observed on Solaris
       64-bit systems. (Bug #16021177)

     * InnoDB: ALTER TABLE for InnoDB tables was not fully atomic.
       (Bug #15989081)

     * InnoDB: When innodb_mirrored_log_groups was set to a value
       other than the default 1, the MySQL server encountered a
       serious error during startup while loading the InnoDB
       memcached plugin. In earlier releases, the server would refuse
       to start (but not display an error) when this setting was
       changed. This fix cleans up the error handling for unsupported
       values of this configuration option. (Bug #15907954, Bug
       #67670)

     * InnoDB: An error at the filesystem level, such as too many
       open files, could cause an unhandled error during an ALTER
       TABLE operation. The error could be accompanied by Valgrind
       warnings, and by this assertion message:
       Assertion `! is_set()' failed.
       mysqld got signal 6 ;
       (Bug #14628410, Bug #16000909)

     * InnoDB: The INNODB_SYNC_ARRAY_SIZE variable was incorrectly
       allowed to be configured at runtime. As documented,
       INNODB_SYNC_ARRAY_SIZE must be configured when the MySQL
       instance is starting up, and cannot be changed afterward. This
       fix changes INNODB_SYNC_ARRAY_SIZE to a non-dynamic variable,
       as intended. (Bug #14629979)

     * InnoDB: The server could exit during an attempt by InnoDB to
       reorganize or compress a compressed secondary index page. (Bug
       #14606334)

     * InnoDB: A RENAME TABLE statement could stall for several
       minutes before timing out. This issue could occurred for a
       table using compression
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_com
       pression), with change buffering
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_cha
       nge_buffering) enabled. (Bug #14556349)

     * InnoDB: A DML operation performed while a RENAME TABLE
       operation waits for pending I/O operations on the tablespace
       to complete would result in a deadlock. (Bug #14556349)

     * InnoDB: If the server was started with the skip-innodb option,
       or InnoDB otherwise failed to start, query any of these
       Information Schema tables would cause a severe error:

          + INNODB_BUFFER_PAGE

          + INNODB_BUFFER_PAGE_LRU

          + INNODB_BUFFER_POOL_STATS
       (Bug #14144290)

     * InnoDB: Online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_onl
       ine_ddl) had a restriction that prevented renaming a column
       and adding a foreign key involving that column in a single
       ALTER TABLE statement. Now, this combination of operations is
       allowed in a single statement. (Bug #14105491)

     * InnoDB: When printing out long semaphore wait diagnostics,
       sync_array_cell_print() ran into a segmentation violation
       (SEGV) caused by a race condition. This fix addresses the race
       condition by allowing the cell to be freed while it is being
       printed. (Bug #13997024)

     * InnoDB: The value of the innodb_version variable was not
       updated consistently for all server releases for the InnoDB
       Plugin in MySQL 5.1, and the integrated InnoDB component in
       MySQL 5.5, 5.6, and higher. Since InnoDB and MySQL Server
       development cycles are fully integrated and synchronized, now
       the value returned by the innodb_version variable is the same
       as for the version variable. (Bug #13463493, Bug #63435)

     * InnoDB: Killing a query caused an InnoDB assertion failure
       when the same table (cursor) instance was used again. This is
       the result of a regression error introduced by the fix for
       Bug#14704286. The fix introduced a check to handle kill
       signals for long running queries but the cursor was not
       restored to the proper state. (Bug #68051, Bug #16088883)

     * InnoDB: On startup, InnoDB reported a message on 64-bit Linux
       and 64-bit Windows systems stating that the CPU does not
       support crc32 instructions. On Windows, InnoDB does not use
       crc32 instructions even if supported by the CPU. This fix
       revises the wording of the message and implements a check for
       availability of crc32 instructions. (Bug #68035, Bug
       #16075806)

     * InnoDB: The length of internally generated foreign key names
       was not checked. If internally generated foreign key names
       were over the 64 character limit, this resulted in invalid DDL
       from SHOW CREATE TABLE. This fix checks the length of
       internally generated foreign key names and reports an error
       message if the limit is exceeded. (Bug #44541, Bug #11753153)

     * InnoDB: This fix removes left-over prototype code for
       srv_parse_log_group_home_dirs, and related header comments.
       (Bug #68133, Bug #16198764)

     * InnoDB: Attempting to replace the default InnoDB FTS stopword
       list by creating an InnoDB table with the same structure as
       INFORMATION_SCHEMA.innodb_ft_default_stopword would result in
       an error. SHOW CREATE TABLE revealed that the new InnoDB table
       was created with CHARSET=utf8. The InnoDB FTS stopword table
       validity check only supported latin1. This fix extends the
       validity check for all supported character sets. (Bug #68450,
       Bug #16373868)

     * Partitioning: ALGORITHM = INPLACE, which was disallowed in
       MySQL 5.6.10 for DDL statements operating on partitioned
       tables, can once again be used with such statements. (Bug
       #16216513)
       References: See also Bug #14760210.

     * Partitioning: A query on a table partitioned by range and
       using TO_DAYS() as a partitioing function always included the
       first partition of the table when pruning. This happened
       regardless of the range employed in the BETWEEN clause of such
       a query. (Bug #15843818, Bug #49754)

     * Partitioning: Execution of ALTER TABLE ... DROP PARTITION
       against a view caused the server to crash, rather than fail
       with an error as expected. (Bug #14653504)

     * Partitioning: A query result was not sorted if both DISTINCT
       and ORDER BY were used and the underlying table was
       partitioned. (Bug #14058167)

     * Partitioning: Inserting any number of rows into an ARCHIVE
       table that used more than 1000 partitions and then attempting
       to drop the table caused the MySQL Server to fail. (Bug
       #13819630, Bug #64580)

     * Replication: When using GTIDs and binary log auto-positioning,
       the master had to scan all binary logs whenever the slave
       reconnected (due to reasons such as I/O thread failure or a
       change of master) before it could send any events to slave.
       Now, the master starts from the oldest binary log that
       contains any GTID not found on the slave. (Bug #16340322, Bug
       #68386)

     * Replication: When the server version of the master was greater
       than or equal to 10, replication to a slave having a lower
       server version failed. (Bug #16237051, Bug #68187)

     * Replication: When replicating to a MySQL 5.6 master to an
       older slave, Error 1193 (ER_UNKNOWN_SYSTEM_VARIABLE) was
       logged with a message such as Unknown system variable
       'SERVER_UUID' on master, maybe it is a *VERY OLD MASTER*. This
       message has been improved to include more information, similar
       to this one: Unknown system variable 'SERVER_UUID' on master.
       A probable cause is that the variable is not supported on the
       master (version: 5.5.31), even though it is on the slave
       (version: 5.6.11). (Bug #16216404, Bug #68164)

     * Replication: A zero-length name for a user variable (such as
       @``) was incorrectly considered to be a sign of data or
       network corruption when reading from the binary log. (Bug
       #16200555, Bug #68135)

     * Replication: When MTS is on and transactions are being
       applied, the slave coordinator would hang when encountering a
       checksum error on a transaction event. This was due to a
       deadlock situation in which the coordinator assumed a normal
       stop while a worker waited for the coordinator to dispatch
       more events. For debug builds, the problem appeared as an
       assertion failure, which was due to the coordinator not
       setting thd->is_error() when encountering an error. (Bug
       #16210351)

     * Replication: mysqlbinlog can connect to a remote server and
       read its binary logs. In MySQL 5.6 and later, this tool can
       also wait for the server to generate and send additional
       events, in practice behaving like a slave connecting to a
       master. In cases where the server sent a heartbeat,
       mysqlbinlog was unable to handle it properly. As a
       consequence, mysqlbinlog failed at this point, without reading
       any more events from the server. To fix this problem,
       mysqlbinlog now ignores any binary log events of type
       HEARTBEAT_LOG_EVENT that it receives. (Bug #16104206)

     * Replication: STOP SLAVE could cause a deadlock when issued
       concurrently with a statement such as SHOW STATUS that
       retrieved the values for one or more of the status variables
       Slave_retried_transactions, Slave_heartbeat_period,
       Slave_received_heartbeats, Slave_last_heartbeat, or
       Slave_running. (Bug #16088188, Bug #67545)
       References: See also Bug #16088114.

     * Replication: Using the --replicate-* options (see Replication
       Slave Options and Variables
       (http://dev.mysql.com/doc/refman/5.6/en/replication-options-sl
       ave.html)) could in some cases lead to a memory leak on the
       slave. (Bug #16056813, Bug #67983)

     * Replication: Backtick (`) characters were not always handled
       correctly in internally generated SQL statements, which could
       sometimes lead to errors on the slave. (Bug #16084594, Bug
       #68045)
       References: This bug is a regression of Bug #14548159, Bug
       #66550.

     * Replication: The session-level value for gtid_next was
       incorrectly reset on the slave for all rollbacks, which meant
       that GTIDs could be lost for multi-statement transactions,
       causing the slave to stop with an
       ER_GTID_NEXT_TYPE_UNDEFINED_GROUP error. Now this is done only
       when a complete transaction is being rolled back, or when
       autocommit is enabled. (Bug #16084206)

     * Replication: In order to provision or to restore a server
       using GTIDs, it is possible to set gtid_purged to a given GTID
       set listing the transactions that were imported. This
       operation requires that the global gtid_executed and
       gtid_purged server system variables are empty. (This is done
       in order to avoid the possibility of overriding
       server-generated GTIDs.)
       The error message GTID_PURGED can only be set when
       GTID_EXECUTED is empty that was raised when this requirement
       was not met could be confusing or misleading because it did
       not specify the scope of the affected variables. To prevent
       this from happening, error messages that refer to variables
       relating to GTIDs now specify the scope of any such variables
       when they do so. (Bug #16084426, Bug #68038)

     * Replication: In certain cases, the dump thread could send a
       heartbeat out of synchronisation with format description
       events. One of the effects of this issue what that, after
       provisioning a new server from a backup data directory and
       setting --gtid-mode=ON and enabling autopositioning (see
       CHANGE MASTER TO Syntax
       (http://dev.mysql.com/doc/refman/5.6/en/change-master-to.html)
       ), replication failed to start, with the error Read invalid
       event from master.... The same problem could also cause
       GTID-based replication to fail due to skipped events following
       a unplanned shutdown of the master. (Bug #16051857)

     * Replication: In some cases, when the slave could not recognize
       the server version of the master, this could cause the slave
       to fail. (Bug #16056365)

     * Replication: Table IDs used in replication were defined as
       type ulong on the master and uint on the slave. In addition,
       the maximum value for table IDs in binary log events is 6
       bytes (281474976710655). This combination of factors led to
       the following issues:

          + Data could be lost on the slave when a table was assigned
            an ID greater than uint.

          + Table IDs greater than 281474976710655 were written to
            the binary log as 281474976710655.

          + This led to a stopped slave when the slave encountered
            two tables having the same table ID.
       To fix these problems, IDs are now defined by both master and
       slave as type ulonglong but constrained to a range of 0 to
       281474976710655, restarting from 0 when it exceeds this value.
       (Bug #14801955, Bug #67352)

     * Replication: Internal objects used for relay log information
       were only partially deleted before freeing their memory. (Bug
       #14677824)

     * Replication: It was possible in certain cases---immediately
       after detecting an EOF in the dump thread read event loop, and
       before deciding whether to change to a new binary log
       file---for new events to be written to the binary log before
       this decision was made. If log rotation occurred at this time,
       any events that occurred following EOF detection were dropped,
       resulting in loss of data. Now in such cases, steps are taken
       to make sure that all events are processed before allowing the
       log rotation to take place. (Bug #13545447, Bug #67929)
       References: See also Bug #16016886.

     * Replication: If the disk becomes full while writing to the
       binary log, the server hangs until space is freed up manually.
       It was possible after this was done for the MySQL server to
       fail, due to an internal status value being set when not
       needed. Now in such cases, rather than trying to set this
       status, a warning is written in the error log instead. (Bug
       #11753923, Bug #45449)

     * Microsoft Windows: In Shared Memory mode
       (http://dev.mysql.com/doc/refman/5.6/en/server-options.html#op
       tion_mysqld_shared-memory), the MySQL Server could crash when
       receiving requests from multiple threads. (Bug #13934876)

     * Failure to handle a full-text search wildcard properly could
       cause the server to exit. (Bug #16446108)

     * InnoDB now reports row and table locks to the thread pool
       plugin. Deadlocks within a thread group could occur otherwise.
       (Bug #16448639)

     * SHOW ENGINE PERFORMANCE_SCHEMA STATUS could report incorrect
       memory-allocation values when the correct values exceeded 4GB.
       (Bug #16414644)

     * Performance Schema statement tokenization overhead was
       reduced. (Bug #16382260)

     * A long database name in a GRANT statement could cause the
       server to exit. (Bug #16372927)

     * On Linux, a race condition involving epoll() could cause the
       thread pool plugin to miss events. This was most likely on
       systems with greater than 16 cores. (Bug #16367483)

     * The server could exit if a prepared statement attempted to
       create a table using the name of an existing view while an SQL
       handler was opened. (Bug #16385711)

     * For debug builds, checking of password constraints could raise
       an assertion for statements that updated passwords. (Bug
       #16289303)

     * The BUILD-CMAKE file in MySQL distributions was updated with
       the correct URL for CMake information. (Bug #16328024)

     * A Valgrind failure could occur if a CREATE USER statement was
       logged to the general query log and the old_passwords system
       variable was set to 2. (Bug #16300620)

     * The optimizer's attempt to remove redundant subquery clauses
       raised an assertion when executing a prepared statement with a
       subquery in the ON clause of a join in a subquery. (Bug
       #16318585)
       References: This bug is a regression of Bug #15875919.

     * Very small join_buffer_size values could cause an assertion to
       be raised. (Bug #16328373)

     * Some aggregate queries attempted to allocate excessive memory.
       (Bug #16343992)

     * Incorrect results were returned if a query contained a
       subquery in an IN clause which contained an XOR operation in
       the WHERE clause. (Bug #16311231)

     * For debug builds, an assertion could be raised if a statement
       failed with autocommit enabled just before an XA START
       statement was issued. (Bug #16341673)

     * Conversion of numeric values to BIT could yield unexpected
       results. (Bug #16271540)

     * Certain legal HAVING clauses were rejected as invalid. (Bug
       #16221433)

     * Fixed warnings when compiling with XCode 4.6. Fixed warnings
       when compiling when the _XOPEN_SOURCE or isoctal macro was
       already defined in the environment. (Bug #16265300, Bug
       #60911, Bug #12407384)

     * Queries using range predicates that were evaluated using the
       LooseScan semi-join strategy could return duplicate rows. (Bug
       #16221623)
       References: This bug is a regression of Bug #14728469.

     * In the range optimizer, an index merge failure could cause a
       server exit. (Bug #16241773)

     * A full-text query using Boolean mode could return zero results
       in some cases where the search term was a quoted phrase:

          + If the quoted phrase was preceded by a + sign. For
            example, this combination of a Boolean + operator and a
            phrase would return zero results:
            where match(content) against('+"required term due to plus
            sign"' in boolean mode)

          + If the quoted phrase contained any stopwords. For
            example, the stopword "the" inside the phrase caused the
            query to return zero results:
            where match(content) against('"stopword inside the phrase"'
            in boolean mode)

       (Bug #16206253, Bug #68150)

     * For debug builds, the server could exit due to incorrect
       calculation of applicable indexes for a join that involved
       const tables. (Bug #16165832)

     * A bug in range optimization sometimes led to incorrect
       condition calculation for index merge union. This could lead
       to missing rows. (Bug #16164031, Bug #68194, Bug #16229746)

     * The Performance Schema could return incorrect values for the
       PROCESSLIST_INFO column of the threads table. (Bug
       #16215165)

     * Invocation of the range optimizer for a NULL select caused the
       server to exit. (Bug #16192219)

     * mysql_config --libs displayed incorrect output. (Bug
       #16200717)

     * For a CREATE TABLE (... col_name TIMESTAMP DEFAULT
       CURRENT_TIMESTAMP ...) ... SELECT statement for which the
       SELECT did not provide a value for the TIMESTAMP column, that
       column was set to '0000-00-00 00:00:00', not the current
       timestamp. (Bug #16163936)

     * yaSSL did not perform proper padding checks, but instead
       examined only the last byte of plaintext and used it to
       determine how many bytes to remove. (Bug #16218104)

     * Using GROUP BY WITH ROLLUP in a prepared statement could cause
       the server to exit. (Bug #16163596)

     * If, in a SELECT, the HAVING clause contained a function call
       which itself contained an alias to a selected expression, the
       server could sometimes exit. (Bug #16165981)

     * Setting the slave_rows_search_algorithms system variable to an
       inappropriate value could cause the server to exit. (Bug
       #16074161)

     * Directory name manipulation could result in stack overflow on
       Mac OS X and Windows. (Bug #16066243)

     * With statement-based binary logging, dropping a TEMPORARY
       InnoDB table could cause a segmentation fault. (Bug #16076275)

     * For debug builds, if the server was started with binary
       logging disabled, executing SHOW RELAYLOG EVENTS from within a
       stored procedure raised an assertion. (Bug #16043173)

     * The query parser leaked memory for some syntax errors. (Bug
       #16040022)

     * With the thread pool plugin enabled, large numbers of
       connections could lead to a Valgrind panic or failure of
       clients to be able to connect. (Bug #16088658, Bug #16196591)

     * The server executed EXPLAIN FORMAT=JSON for some malformed
       queries improperly. (Bug #16078557)

     * Performance Schema instrumentation was missing for slave
       worker threads. (Bug #16083949)

     * The initial test database contained a dummy.bak file that
       prevented DROP DATABASE from working. This file is no longer
       included. Also, a db.opt file is now included that contains
       these lines:
       default-character-set=latin1
       default-collation=latin1_swedish_ci
       (Bug #16062056)

     * Setting a system variable to DEFAULT could cause the server to
       exit. (Bug #16044655)

     * SET PASSWORD and GRANT ... IDENTIFIED BY have no effect on the
       password of a user who is authenticated using an
       authentication plugin that accesses passwords stored
       externally to the mysql.user table. But attempts to change the
       password of such a user produced no warning, leading to the
       impression that the password had been changed when it was not.
       Now MySQL issues an ER_SET_PASSWORD_AUTH_PLUGIN warning to
       indicate that the attempt was ignored. (Bug #16072004)

     * For debug builds, creating an InnoDB table in strict SQL mode
       that violated the maximum key length limit caused the server
       to exit. (Bug #16035659)

     * Issuing a PREPARE statement using certain combinations of
       stored functions and user variables caused the server to exit.
       (Bug #16056537)

     * Joins of exactly 32 tables and containing a HAVING clause
       returned an empty result. (Bug #15972635)

     * A mysys library string-formatting routine could mishandle
       width specifiers. (Bug #15960005)

     * The --character-set-server option could set connection
       character set system variables to values such as ucs2 that are
       not permitted. (Bug #15985752)

     * During shutdown, the server could attempt to lock an
       uninitialized mutex. (Bug #16016493)

     * The --default-authentication-plugin option permitted invalid
       plugin values, and did not always set the old_passwords system
       variable to a value appropriate for the named plugin. (Bug
       #16014394)

     * Under some circumstances, mysql --secure-auth permitted
       passwords to be sent to the server using the old (pre-4.1)
       hashing format. (Bug #15977433)

     * With index condition pushdown enabled, queries for which the
       pushed-down condition contained no columns in the used index
       could be slow. (Bug #15896009)

     * Table creation operations added entries to the Performance
       Schema file_instances table, but these were not always removed
       for table drop operations. (Bug #15927620)

     * In special cases, the optimizer did not consider indexes that
       were applicable to query processing, resulting in potentially
       suboptimal execution and incorrect EXPLAIN output. (Bug
       #15849135, Bug #16094171)

     * A query with an EXISTS/IN/ALL/ANY subquery with an ORDER BY
       clause ordering by an outer column of type BLOB that is not in
       the select list caused an assertion to fire. (Bug #15875919)
       References: See also Bug #14728142.

     * Creating an InnoDB table with a FULLTEXT index could encounter
       a serious error if the table name contained nonalphanumeric
       characters. (Bug #14835178, Bug #16036699)

     * Enabling the query cache during high client contention could
       cause the server to exit. (Bug #14727815)

     * The server sometimes failed to respect
       MAX_CONNECTIONS_PER_HOUR limits on user connections. (Bug
       #14627287)

     * The optimizer could return incorrect results after
       transforming an IN subquery with aggregate functions to an
       EXISTS subquery. (Bug #14586710)

     * When a client program loses the connection to the MySQL server
       or if the server begins a shutdown after the client has
       executed mysql_stmt_prepare(), the next mysql_stmt_prepare()
       returns an error (as expected) but subsequent
       mysql_stmt_execute() calls crash the client. (Bug #14553380)

     * Previously, if multiple --login-path options were given,
       mysql_config_editor ignored all but the last one. Now multiple
       --login-path options result in an error. (Bug #14551712)

     * SET PASSWORD for anonymous users did not work correctly. (Bug
       #14561102)

     * SHOW COLUMNS on a view defined as a UNION of Geometry columns
       could cause the server to exit. (Bug #14362617)

     * The sha256_password_private_key_path and
       sha256_password_public_key_path system variables indicate key
       files for the sha256_password authentication plugin, but the
       server failed to properly check whether the key files were
       valid. Now in the event that either key file is invalid, the
       server logs an error and exits. (Bug #14360513)

     * SET var_name = VALUES(col_name) could cause the server to
       exit. This syntax is now prohibited because in SET context
       there is no column name and the statement returns
       ER_BAD_FIELD_ERROR. (Bug #14211565)

     * The COM_CHANGE_USER command in the client/server protocol did
       not properly use the character set number in the command
       packet, leading to incorrect character set conversion of other
       values in the packet. (Bug #14163155)

     * Invoking the FORMAT() function with a locale and a very large
       number could cause the server to exit. (Bug #14040155)

     * yaSSL rejected some valid server SSL certificates. (Bug
       #13777928)

     * Certain plugin-related conditions can make a user account
       unusable:

          + The account requires an authentication plugin that is not
            loaded.

          + The account requires the sha256_password authentication
            plugin but the server was started with neither SSL nor
            RSA enabled as required by this plugin.

       The server now checks those conditions by default and produces
       warnings for unusable accounts. This checking slows down
       server initialization and FLUSH PRIVILEGES, so it is made
       optional by means of the new validate_user_plugins system
       variable. This variable is enabled by default, but if you do
       not require the additional checking, you can disable it at
       startup to avoid the performance decrement. (Bug #13010061,
       Bug #14506305)

     * Passing an unknown time zone specification to CONVERT_TZ()
       resulted in a memory leak. (Bug #12347040)

     * The obsolete linuxthreads.txt and glibc-2.2.5.patch files in
       the Docs directory of MySQL distributions have been removed.
       (Bug #11766326)

     * mysql_install_db did not escape '_' in the host name for
       statements written to the grant tables. (Bug #11746817)

     * mysqld_safe used the nonportable -e test construct. (Bug
       #67976, Bug #16046140)

     * An out-of-memory condition could occur while handling an
       out-of-memory error, leading to recursion in error handling.
       (Bug #49514, Bug #11757464)

     * The optimizer used loose index scan for some queries for which
       this access method is inapplicable. (Bug #42785, Bug
       #11751794)

     * If a dump file contained a view with one character set and
       collation defined on a view with a different character set and
       collation, attempts to restore the dump file failed with an
       "illegal mix of collations" error. (Bug #65382, Bug #14117025)

     * The REPLACE() function produced incorrect results when a user
       variable was supplied as an argument and the operation was
       performed on multiple rows. (Bug #49271, Bug #11757250)

     * UNION type conversion could incorrectly turn unsigned values
       into signed values. (Bug #49003, Bug #11757005)

     * UNION ALL on BLOB columns could produce incorrect results.
       (Bug #50136, Bug #11758009)

     * View access in low memory conditions could raise a debugging
       assertion. (Bug #39307, Bug #11749556)

     * Queries with many values in a IN() clause were slow due to
       inclusion of debugging code in non-debugging builds. (Bug
       #68046, Bug #16078212)
       References: See also Bug #58731, Bug #11765737.

     * Setting max_connections to a value less than the current
       number of open connections caused the server to exit. (Bug
       #44100, Bug #11752803)

     * Some table I/O performed by the server when calling a storage
       engine were missing from the statistics collected by the
       Performance Schema. (Bug #68180, Bug #16222630)

     * For debug builds, some queries with SELECT ... FROM DUAL
       nested subqueries raised an assertion. (Bug #60305, Bug
       #11827369)

     * Nonspatial indexes only support exact-match lookups for
       spatial columns, but the optimizer incorrectly used range
       access in some cases, leading to incorrect results. (Bug
       #67889, Bug #15993693)

     * If mysql is built with the bundled libedit library, the
       library is built as static code, to avoid linking to a
       different dynamic version at runtime. Dynamic linking could
       result in use of a different, incompatible version and a
       segmentation fault. (Bug #68231, Bug #16296509)

     * The --log-slow-admin-statements and
       --log-slow-slave-statements command options now are exposed at
       runtime as the log_slow_admin_statements and
       log_slow_slave_statements system variables. Their values can
       be examined using SHOW VARIABLES. The variables are dynamic,
       so their values can can be set at runtime. (The options were
       actually replaced by the system variables, but as system
       variables can be set at server startup, no option
       functionality is lost.) (Bug #59860, Bug #11766693)

     * For arguments with fractional seconds greater than six
       decimals, SEC_TO_TIME() truncated, rather than rounding as it
       should have. (Bug #68061, Bug #16093024)

     * MySQL failed to build if configured with WITH_LIBWRAP enabled.
       (Bug #67018, Bug #16342793)

     * If the server was started without a --datadir option, SHOW
       VARIABLES could show an empty value for the datadir system
       variable. (Bug #60995, Bug #12546953)

     * Configuring with -DWITH_SSL=/path/to/openssl resulted in link
       errors due to selection of the incorrect libcrypto. (Bug
       #68277, Bug #16284051)

     * ALTER TABLE tbl_name ADD COLUMN col_name TIMESTAMP DEFAULT
       CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP inserted
       0000-00-00 00:00:00 rather than the current timestamp if the
       alteration was done in place rather than by making a table
       copy. (Bug #68040, Bug #16076089)

     * If the server was started with --skip-grant-tables, ALTER USER
       ... PASSWORD EXPIRE caused the server to exit. (Bug #68300,
       Bug #16295905)

     * CMake did not check whether the system zlib had certain
       functions required for MySQL, resulting in build errors. Now
       it checks and falls back to the bundled zlib if the functions
       are missing. (Bug #65856, Bug #14300733)

     * mysql_install_db did not work in Solaris 10 sparse root zones.
       (Bug #68117, Bug #16197860)

     * For EXPLAIN DELETE and EXPLAIN UPDATE the possible_keys column
       listed all indexes, not just the applicable indexes. (Bug
       #67830, Bug #15972078)

     * The Perl version of mysql_install_db mishandled some error
       messages. (Bug #68118, Bug #16197542)

     * Handling of SQL_CALC_FOUND_ROWS in combination with ORDER BY
       and LIMIT could lead to incorrect results for FOUND_ROWS().
       (Bug #68458, Bug #16383173)

     * Adding an ORDER BY clause following an IN subquery could cause
       duplicate rows to be returned. (Bug #68330, Bug #16308085)

     * If INET6_NTOA() or INET6_ATON() returned NULL for a row in a
       result set, following rows also returned NULL. (Bug #68454,
       Bug #16373973)

     * A statement with an aggregated, nongrouped outer query and an
       aggregated, nongrouped subquery in the SELECT list could
       return incorrect results. (Bug #68372, Bug #16325175)

     * With explicit_defaults_for_timestamp enabled, inserting NULL
       into a TIMESTAMP NOT NULL column now produces an error (as it
       already did for other NOT NULL data types), instead of
       inserting the current timestamp. (Bug #68472, Bug #16394472)

Changes in MySQL Connector/ODBC 5.2.4 (5 February, 2013)

   This release fixes any bugs encountered since Connector/ODBC
   5.2.3. Its main focus is on compatibility with the latest features
   of MySQL 5.6.

   Functionality Added or Changed

     * The new connection option can_handle_exp_pwd indicates that
       your application includes error-handling logic to deal with
       the error code for an expired password. See Connector/ODBC
       Connection Parameters
       (http://dev.mysql.com/doc/refman/5.5/en/connector-odbc-configu
       ration-connection-parameters.html) for the details of this
       connection option and the associated SQL state and native
       error code. See ALTER USER Syntax
       (http://dev.mysql.com/doc/refman/5.6/en/alter-user.html) for
       details about password expiration for MySQL server accounts.
       This new option is added to the Windows GUI, through a
       checkbox Can Handle Expired Password on the Connection tab of
       the Details dialog.

     * The following reserved words were added to the list returned
       by the SQLGetInfo() ODBC function, for compatibility with the
       latest MySQL 5.6 syntax:

          + GET

          + IO_AFTER_GTIDS

          + IO_BEFORE_GTIDS

          + MASTER_BIND

          + ONE_SHOT

          + PARTITION

          + SQL_AFTER_GTIDS

          + SQL_BEFORE_GTIDS

   Bugs Fixed

     * When a column with type TINYTEXT, TEXT, MEDIUMTEXT, or
       LONGTEXT was retrieved from a table with a binary collation,
       the text fields were converted to a hexadecimal
       representation, even though these values were not really
       BLOBs. The unnecessary conversion could expand the data,
       causing overflow problems when storing the result values. (Bug
       #11746572, Bug #27282)

Changes in MySQL Connector/ODBC 5.1.12 (5 February, 2013)

   Functionality Added or Changed

     * The new connection option can_handle_exp_pwd indicates that
       your application includes error-handling logic to deal with
       the error code for an expired password. See Connector/ODBC
       Connection Parameters
       (http://dev.mysql.com/doc/refman/5.5/en/connector-odbc-configu
       ration-connection-parameters.html) for the details of this
       connection option and the associated SQL state and native
       error code. See ALTER USER Syntax
       (http://dev.mysql.com/doc/refman/5.6/en/alter-user.html) for
       details about password expiration for MySQL server accounts.
       This new option is added to the Windows GUI, through a
       checkbox Can Handle Expired Password on the Connection tab of
       the Details dialog.

     * The following reserved words were added to the list returned
       by the SQLGetInfo() ODBC function, for compatibility with the
       latest MySQL 5.6 syntax:

          + GET

          + IO_AFTER_GTIDS

          + IO_BEFORE_GTIDS

          + MASTER_BIND

          + ONE_SHOT

          + PARTITION

          + SQL_AFTER_GTIDS

          + SQL_BEFORE_GTIDS

   Bugs Fixed

     * The string returned by the SQLNativeSql function was not
       null-terminated as it should be. (Bug #14559721)

     * Specifying certain values for the CHARSET option in the
       connection string could cause a serious error when a query was
       executed. (Bug #14363601)

     * If multiple statements were called using the same statement
       handle, SQLColumns and possibly other catalog functions could
       return wrong results. Some field length values were not reset
       in the descriptor records. The issue occurred even if the
       statement handle was closed with SQL_CLOSE between the
       statements. (Bug #14338051)

     * If an application received a SIGPIPE signal, then another
       SIGPIPE signal immediately after (before the first signal
       handler was finished), the application could terminate rather
       than handling the second signal. (Bug #14303803)

     * Several catalog or info functions could raise an incorrect
       error String data, right truncated when only partial
       information was requested. For example, if the application
       called SQLDescribeCol(hstmt, ColNumber, ColName, BufferLen,
       ....), but did not want the column name (ColName == NULL and
       BufferLen == 0). SQL_SUCCESS_WITH_INFO could also be returned
       rather than the correct value SQL_SUCCESS. This issue affected
       many ADO, DAO, and other applications.
       Affected functions include:
Spurious error and incorrect return code:

SQLDescribeCol
SQLDescribeColA
SQLDescribeColW
SQLGetInfoA
SQLGetInfoW

Incorrect return code:

SQLColAttribute
SQLColAttributeW
SQLGetConnectAttr
SQLGetConnectAttrW
SQLGetCursorName
SQLGetCursorNameW
SQLGetInfo
SQLGetInfoW
SQLNativeSql
SQLNativeSqlW
       (Bug #14285620)

     * Calling the SQLTables function with a very long database or
       table name could cause a serious error. This fix allows the
       SQLTables function to accept database and table names with the
       maximum length of 64 characters. (Bug #14085211)

     * On a 64-bit system, calls to the SQLBindCol function using
       indicator variables (through the last parameter) could return
       incorrect results. (Bug #11766437, Bug #59541)

     * The symbols SQLInstallDriverEx, SQLInstallDriverExW, and
       SQLRemoveDriverW were exported, causing incompatibility with
       some commercial ODBC packages such as DataDirect ODBC, and
       making Connector/ODBC dependent on the unixODBC library
       libodbcinst.so.1. This issue was first observed in
       Connector/ODBC 5.1.8. (Bug #11766724, Bug #59900)

     * When a column with type TINYTEXT, TEXT, MEDIUMTEXT, or
       LONGTEXT was retrieved from a table with a binary collation,
       the text fields were converted to a hexadecimal
       representation, even though these values were not really
       BLOBs. The unnecessary conversion could expand the data,
       causing overflow problems when storing the result values. (Bug
       #11746572, Bug #27282)

Changes in MySQL Connector/CPP 1.1.2 (5 February, 2013)

   Bugs Fixed

     * Connector/C++ applications could not handle connecting to the
       server using an account for which the password had expired.
       Connector/C++ now supports three new connection options:

          + OPT_CAN_HANDLE_EXPIRED_PASSWORDS: If true, this indicates
            to the driver that the application can handle expired
            passwords.
            If the application specifies
            OPT_CAN_HANDLE_EXPIRED_PASSWORDS but the underlying
            libmysql library does not support it, the driver returns
            sql::mysql:deCLIENT_DOESNT_SUPPORT_FEATURE(820).

          + preInit: A string containing queries to run before driver
            initialization.

          + postInit: A string containing queries to run after driver
            initialization.
       A new file driver/mysql_error.h is being added to the MSI
       package. This file defines an enum DRIVER_ERROR, which
       contains the definition of deCL_CANT_HANDLE_EXP_PWD.
       In addition to the preceding changes, these problems with
       Statement::executeUpdate were fixed:

          + If Statement::executeUpdate executed multiple statements,
            the connection became unusable.

          + There was no exception if one of queries returned a
            resultset. Now executeUpdate returns and update count for
            the last executed query.
       For example code showing how to use the new options, see the
       file test/unit/bugs/bugs.cpp in the Connector/C++
       distribution. (Bug #67325, Bug #15936764)

-----------------------------------------
Changes in MySQL 5.6.10 (5 February 2013)

   Beginning with MySQL 5.6.10, MySQL Enterprise Edition is available
   for MySQL 5.6. Specifically, MySQL Enterprise 5.6.10 includes
   these components previously available only in MySQL 5.5: MySQL
   Enterprise Security (PAM and Windows authentication plugins),
   MySQL Enterprise Audit, and MySQL Thread Pool. For information
   about these features, see MySQL Enterprise Edition
   ( http://dev.mysql.com/doc/refman/5.6/en/mysql-enterprise.html ).
   To learn more about commercial products, see
   http://www.mysql.com/products/ .

   Known limitations of this release:

   On Microsoft Windows, when using the MySQL Installer to install
   MySQL Server 5.6.10 on a host with an existing MySQL Server of a
   different version (such as 5.5.30), that also has a different
   license (community versus commercial), you must first update the
   license type of the existing MySQL Server. Otherwise, MySQL
   Installer will remove MySQL Server(s) with different licenses from
   the one you chose with MySQL Server 5.6.10.

   On Microsoft Windows 8, updating a community release to a
   commercial release requires you to manually restart the MySQL
   service after the update.

   Functionality Added or Changed

     * Replication: An Auto_Position column has been added to the
       output generated by SHOW SLAVE STATUS. The value of this
       column shows whether replication autopositioning is in use. If
       autopositioning is enabled---that is, if MASTER_AUTO_POSITION
       = 1 was set by the last successful CHANGE MASTER TO statement
       that was executed on the slave---then the column's value is 1;
       if not, then the value is 0. (Bug #15992220)

     * In RPM packages built for Unbreakable Linux Network,
       libmysqld.so now has a version number. (Bug #15972480)

     * Error messages for ALTER TABLE statement using a LOCK or
       ALGORITHM value not supported for the given operation were
       very generic. The server now produces more informative
       messages. (Bug #15902911)

     * If a client with an expired password connected but
       old_passwords was not the value required to select the
       password hashing format appropriate for the client account,
       there was no way for the client to determine the proper value.
       Now the server automatically sets the session old_passwords
       value appropriately for the account password. (Bug #15892194)

     * The validate_password_policy_number system variable was
       renamed to validate_password_policy. (Bug #14588121)

     * In JSON-format EXPLAIN output, the attached_condition
       information for subqueries now includes select# to indicate
       the relative order of subquery execution. (Bug #13897507)

   Bugs Fixed

     * InnoDB; Performance: Optimized read operations for compressed
       (http://dev.mysql.com/doc/refman/5.6/en/glos_compression.html)
       tables by skipping redundant tests. The check for whether any
       related changes needed to be merged from the insert buffer
       (http://dev.mysql.com/doc/refman/5.6/en/glos_insert_buffer.htm
       l) was being called more often than necessary. (Bug #14329288,
       Bug #65886)

     * InnoDB; Performance: Immediately after a table was created,
       queries against it would not use loose index scans
       (http://dev.mysql.com/doc/refman/5.6/en/loose-index-scan.html)
       . The issue went away following an ALTER TABLE on the table.
       The fix improves the accuracy of the index statistics
       (http://dev.mysql.com/doc/refman/5.6/en/glos_index_statistics.
       html) gathered when the table is first created. (Bug
       #14200010)

     * Replication; Important Change: The lettercasing used for
       displaying UUIDs in global transaction identifiers was
       inconsistent. Now, all GTID values use lowercase, including
       those shown in the Retrieved_Gtid_Set and Executed_Gtid_Set
       columns from the output of SHOW SLAVE STATUS. (Bug #15869441)

     * InnoDB: Under certain circumstances, an InnoDB table was
       reported as corrupted after import using ALTER TABLE ...
       IMPORT TABLESPACE. The problem was accompanied by one of these
       messages:
Warning  : InnoDB: The B-tree of index "PRIMARY" is corrupted.
error    : Corrupt
       or:
Warning  : InnoDB: The B-tree of index "GEN_CLUST_INDEX" is corrupted
.
error    : Corrupt
       This issue occurred intermittently, and primarily affected
       large tables. The REPAIR TABLE statement would fix the problem
       reported by the error message. (Bug #15960850, Bug #67807)

     * InnoDB: Some Valgrind warnings were issued during shutdown,
       while cleaning up a background thread that handles
       optimization of tables containing FULLTEXT indexes. (Bug
       #15994393)

     * InnoDB: If an online DDL operation to add a unique index
       failed, because duplicate items were created by concurrent DML
       during the online DDL operation, the ALTER TABLE operation
       failed with the wrong error type. It returned
       ER_INDEX_CORRUPT; now it returns the new error code
       ER_DUP_UNKNOWN_IN_INDEX. (It does not return ER_DUP_KEY,
       because the duplicate key value is not available to be
       reported when this condition occurs.) (Bug #15920713)

     * InnoDB: ALTER TABLE statements using the online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       feature could cause Valgrind warnings. (Bug #15933178)

     * InnoDB: Names of indexes being created by an online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       operation were being displayed incorrectly in
       information_schema tables while the operation was in progress.
       This fix ensures the table names have the leading 0xff byte
       stripped off for information_schema queries. This change
       affects the columns:

          + innodb_buffer_page.index_name

          + innodb_buffer_page_lru.index_name

          + innodb_cmp_per_index.index_name

          + innodb_cmp_per_index_reset.index_name

          + innodb_locks.lock_index

          + innodb_sys_indexes.name
       (Bug #15946256)

     * InnoDB: The status variable
       Innodb_buffer_pool_read_ahead_evicted could show an inaccurate
       value, higher than expected, because some pages in the buffer
       pool
       (http://dev.mysql.com/doc/refman/5.6/en/glos_buffer_pool.html)
       were incorrectly considered as being brought in by read-ahead
       (http://dev.mysql.com/doc/refman/5.6/en/glos_read_ahead.html)
       requests. (Bug #15859402, Bug #67476)

     * InnoDB: Creating an index on a CHAR column could fail for a
       table with a character set with varying length, such as UTF-8,
       if the table was created with the ROW_FORMAT=REDUNDANT clause.
       (Bug #15874001)

     * InnoDB: If the server crashed near the end of an online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       ALTER TABLE statement, a subsequent CHECK TABLE statement
       using the EXTENDED clause could cause a serious error. (Bug
       #15878013)

     * InnoDB: Specifying an innodb_log_file_size value of 4GB or
       larger was not possible on 64-bit Windows systems. This issue
       only affected debug builds. (Bug #15882860)

     * InnoDB: This fix ensures that in case of a serious unhandled
       error during an ALTER TABLE operation that copies the original
       table, any data that could be needed for data recovery is
       preserved, in tables using names of the form #sql-ib-table_id
       or #mysql50##sql-ib-table_id. (Bug #15866623)

     * InnoDB: An online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       operation to add a primary key
       (http://dev.mysql.com/doc/refman/5.6/en/glos_primary_key.html)
       to a table could encounter a serious error if the table also
       had an index on a column prefix
       (http://dev.mysql.com/doc/refman/5.6/en/glos_column_prefix.htm
       l) of a BLOB column.
       This fix suspends the background purge
       (http://dev.mysql.com/doc/refman/5.6/en/glos_purge.html)
       operation while a table is being rebuilt by an ALTER TABLE
       statement, if any rows containing off-page columns
       (http://dev.mysql.com/doc/refman/5.6/en/glos_off_page_column.h
       tml) would be removed. Currently, to avoid excessive space
       usage during the online DDL operation, avoid these types of
       concurrent DML
       (http://dev.mysql.com/doc/refman/5.6/en/glos_dml.html)
       operations until the ALTER TABLE is finished:

          + DELETE of rows that contain off-page columns.

          + UPDATE of primary key columns in rows that contain
            off-page columns.

          + UPDATE of off-page columns.
       (Bug #14827736)

     * InnoDB: The server could halt with an assertion error while
       creating an index:
InnoDB: Assertion failure in thread thread_num in file row0merge.cc l
ine 465
       This issue affected tables with a combination of
       ROW_FORMAT=REDUNDANT off-page columns
       (http://dev.mysql.com/doc/refman/5.6/en/glos_off_page_column.h
       tml), and an index on a column prefix
       (http://dev.mysql.com/doc/refman/5.6/en/glos_column_prefix.htm
       l). (Bug #14753402)

     * InnoDB: information_schema tables with InnoDB metadata, such
       as innodb_sys_tablestats, displayed non-alphanumeric
       characters in the names of tables using an encoded format, for
       example with @0024 instead of $. (Bug #14550145)

     * InnoDB: With a large value for innodb_buffer_pool_size, and
       innodb_buffer_pool_instances set greater than 1, pages
       (http://dev.mysql.com/doc/refman/5.6/en/glos_page.html) were
       being incorrectly evicted
       (http://dev.mysql.com/doc/refman/5.6/en/glos_eviction.html)
       from the buffer pool
       (http://dev.mysql.com/doc/refman/5.6/en/glos_buffer_pool.html)
       . (Bug #14125092)

     * Partitioning: Partition pruning is now enabled for tables
       using a storage engine that provides automatic partitioning,
       such as the NDB storage engine, but which are explicitly
       partitioned. Previously, pruning was disabled for all tables
       using such a storage engine, whether or not the tables had
       explicitly defined partitions.
       In addition, as part of this fix, explicit partition selection
       is now disabled for tables using a storage engine (such as
       NDB) that provides automatic partitioning. (Bug #14827952)
       References: See also Bug #14672885.

     * Replication: When using GTID-based replication, and whenever a
       transaction was executed on the master but was not sent to the
       slave because the slave already had a transaction with that
       ID, semisynchrononous replication timed out. One case in which
       this could happen was during a failover operation where the
       new master started behind the new slave. (Bug #15985893)

     * Replication: An unnecessary flush to disk performed after
       every transaction when using FILE as the replication info
       repository type could degrade performance. Now this is done
       only when both data and relay log info is stored in
       (transactional) tables. (Bug #15980626)

     * Replication: Issuing START SLAVE UNTIL SQL_BEFORE_GTIDS =
       gtid_set, where gtid_set covered a large number (tens or
       hundreds of millions) of transactions, could cause the server
       to hang. (Bug #15968413)

     * Replication: When a slave was started using --skip-innodb and
       replication info file repositories (FILE being the default for
       both --relay-log-info-repository and
       --master-info-repository), replication was incorrectly
       stopped. However, if the slave is using file repositories and
       not currently migrating between info repositories, replication
       should be able to work without issues. Now the server ignores
       errors raised when trying to open table info repositories in
       such conditions.
       In addition, binary log initialization was not performed
       correctly when starting the slave with --skip-innodb, which
       caused the --log-bin option to be ignored. (Bug #15956714, Bug
       #67798, Bug #15971607)

     * Replication: When temporary and persistent tables, or
       temporary tables using different storage engines, are dropped
       in a single statement, this statement is actually written as
       two statements to the binary log, each represented by its own
       log event. When gtid_mode is ON, each DDL event must have a
       GTID; however, in such cases, the statement dropping the
       temporary table was uncommitted, which meant that it was not
       given its own GTID.
       Now, when a DDL statement dropping a temporary table and a
       table that is persistent, or that uses a different storage
       engine, is separated in the manner just described, and the
       resulting logged statement affecting only the temporary table
       does not implicitly commit, a commit is forced so that the
       corresponding log event has own unique GTID. (Bug #15947962)

     * Replication: When used on a binary log that had been written
       by a GTID-enabled server, mysqlbinlog did not correctly handle
       transactions left unclosed by the omission of statements that
       were ignored when the --database option was employed.
       Now, whenever mysqlbinlog --database reads a GTID log event,
       it checks to see whether there is an unclosed transaction, and
       if so, issues a commit. (Bug #15912728)

     * Replication: Semisynchronous replication did not work
       correctly with GTIDs enabled. (Bug #15927032)
       References: See also Bug #14737388.

     * Replication: When GTIDs were enabled, the automatic dropping
       of a temporary table when a client disconnected did not always
       generate a GTID. Now each logged DROP TABLE statement,
       including any generated by the server, is guaranteed to have
       its own GTID. (Bug #15907504)

     * Replication: After dropping a column from the slave's version
       of a table, then altering the same column of this table on the
       master (so that a type conversion would have been required had
       the column not been droppped on the slave), inserts into this
       table caused replication to fail. (Bug #15888454)

     * Replication: SET GLOBAL sql_slave_skip_counter = 1 did not
       skip errors or update the slave's position in the binary log
       position when using --gtid-mode = ON. (Bug #15833516)

     * Replication: When a binary log is replayed on a server (for
       example, by executing a command like mysqlbinlog binlog.000001
       | mysql), it sets a pseudo-slave mode on the client connection
       used, so that the server can read binlog and apply binary log
       events correctly. However, the pseudo-slave mode was not
       disabled after the binary log dump was read, which caused
       unexpected filtering rules to be applied to SQL statements
       subsequently executed on the same connection. (Bug #15891524)

     * Replication: During mysqld shutdown, global GTID variables
       were released before it was made certain that all plugins had
       stopped using them. (Bug #14798275)

     * Replication: MASTER_POS_WAIT() could hang or return -1 due to
       invalid updates by the slave SQL thread when transactions were
       skipped by the GTID protocol. (Bug #14737388)
       References: See also Bug #15927032.

     * Replication: Trying to execute a Stop event on a multithreaded
       slave could cause unwanted updates to the relay log, leading
       the slave to lose synchronization with the master. (Bug
       #14737388)

     * Replication: Names of databases in binary log query log events
       were not properly checked for length. (Bug #14636219)

     * Replication: Issuing START SLAVE concurrently with setting
       sql_slave_skip_counter or slave_net_timeout could cause a
       deadlock. (Bug #14236151)

     * Replication: When using statement-based replication, and where
       the master and the slave used table schemas having different
       AUTO_INCREMENT columns, inserts generating AUTO_INCREMENT
       values logged for a given table on the master could be applied
       to the wrong table on the slave. (Bug #12669186)

     * Replication: Repeated execution of CHANGE MASTER TO statements
       using invalid MASTER_LOG_POS values could lead to errors and
       possibly a crash on the slave. Now in such cases, the
       statement fails with a clear error message. (Bug #11764602,
       Bug #57454)

     * Microsoft Windows: Dynamic file names (with colons) are no
       longer allowed. Static file names using the Alternate Data
       Stream (ADS) NTFS functionality of Microsoft Windows may
       continue to be used. (Bug #11761752)

     * During client connection processing, the server now performs
       password-expiration checking after SSL checks. (Bug #16103348)

     * A buffer-handling problem in yaSSL was fixed. (Bug #15965288)

     * The plugin logging routine mishandled its argument, resulting
       in undefined behavior. (Bug #16002890)

     * An ALTER TABLE with the ADD PRIMARY KEY or ADD UNIQUE INDEX
       clause could encounter a serious error if the columns for the
       primary key
       (http://dev.mysql.com/doc/refman/5.6/en/glos_primary_key.html)
       or unique index
       (http://dev.mysql.com/doc/refman/5.6/en/glos_unique_index.html
       ) contained duplicate entries. This error occurred
       intermittently, depending on how the rows were physically
       distributed across index blocks. (Bug #15908291)

     * The ALTER TABLE statement can now use the LOCK=NONE clause,
       allowing online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       with concurrent DML
       (http://dev.mysql.com/doc/refman/5.6/en/glos_dml.html), for
       child tables
       (http://dev.mysql.com/doc/refman/5.6/en/glos_child_table.html)
       containing foreign key constraints
       (http://dev.mysql.com/doc/refman/5.6/en/glos_foreign_key_const
       raint.html). (Bug #15912214)

     * In certain rare cases, a query using UpdateXML() could cause
       the server to crash. (Bug #15948580)
       References: See also Bug #13007062.

     * AES_DECRYPT() and AES_ENCRYPT() had memory leaks when MySQL
       was compiled using OpenSSL. (Bug #15909183)

     * Several OpenSSL-related Valgrind warnings were corrected. (Bug
       #15908967)

     * Several OpenSSL-related memory leaks were fixed. (Bug
       #15921729)

     * Very long database names in queries could cause the server to
       exit. (Bug #15912213)

     * Within a stored procedure, executing a multiple-table DELETE
       statement that used a very long table alias could cause the
       server to exit. (Bug #15954896)

     * Very long table aliases in queries could cause the server to
       exit. (Bug #15948123)

     * Metadata locking and table definition cache routines did not
       always check length of names passed to them. (Bug #15954872)

     * A comment added to mysqldump output for the --set-gid-purged
       option was malformed and caused a syntax error when the dump
       file was reloaded. (Bug #15922502)
       References: See also Bug #14832472.

     * Contention in the thread pool during kill processing could
       lead to a Valgrind panic. (Bug #15921866)

     * In the absence of a FULLTEXT index on an InnoDB table, a
       full-text query with COUNT(*) could raise an assertion. (Bug
       #15950531)

     * If an error occurred during the final phase of an online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       operation, some cached metadata about the table might not be
       restored to its original state. This issue typically affected
       operations that renamed a column, and also dropped and
       re-created an index on that column, in the same ALTER TABLE
       statement. This issue did not affect operations that
       reorganize the clustered index
       (http://dev.mysql.com/doc/refman/5.6/en/glos_clustered_index.h
       tml) of the table, such as adding a new primary key. (Bug
       #15866734)

     * In debug builds, the server could not start on 64-bit Windows
       systems when a value of 16 GB or higher was specified for
       innodb_buffer_pool_size. Non-debug builds would likely have
       subtler issues, such as memory being allocated for the buffer
       pool
       (http://dev.mysql.com/doc/refman/5.6/en/glos_buffer_pool.html)
       but not used, or read requests overlooking pages already
       cached in the buffer pool.
       On 32-bit Windows systems, the value of
       innodb_buffer_pool_instances is increased if necessary so that
       no buffer pool instance is larger then 1.3 GB, due to system
       limitations on memory allocation. This automatic adjustment
       needed for 32-bit Windows systems was incorrectly applied to
       64-bit systems also; for systems with 16 GB or larger buffer
       pools, the adjusted value of innodb_buffer_pool_instances
       would exceed the upper limit of 64, causing an assertion error
       in debug builds. (Bug #15883071)

     * A heavy workload of online DDL
       (http://dev.mysql.com/doc/refman/5.6/en/glos_online_ddl.html)
       and concurrent DML
       (http://dev.mysql.com/doc/refman/5.6/en/glos_dml.html) on a
       table on a master
       (http://dev.mysql.com/doc/mysql-monitor/2.3/en/glossary.html#g
       los_master) server could cause errors as the changes were
       replicated to slave
       (http://dev.mysql.com/doc/mysql-monitor/2.3/en/glossary.html#g
       los_slave) servers. For example, processing a DROP COLUMN
       operation at the same time as queries referring to the dropped
       column could cause errors on slave servers if the statements
       finished in a different order than on the master. (Bug
       #15878880)

     * If the server shut down unexpectedly, the presence of an
       InnoDB table with 1018 columns (very close to the upper limit
       of 1020 columns) could cause an assertion error during server
       restart:
InnoDB: Failing assertion: table->n_def == table->n_cols - 3
       (Bug #15834685)

     * The Performance Schema normally ignores temporary table
       events. User-defined temporary tables are truncated by being
       re-created, but the Performance Schema did not recognize
       re-created temporary tables as being temporary and raised an
       assertion. (Bug #15884836)

     * The Performance Schema session_connect_attrs table displayed
       extraneous information. (Bug #15864703)

     * Subqueries with COUNT(DISTINCT ...)) could cause the server to
       exit. (Bug #15832620)
       References: See also Bug #11750963.

     * Rows_log_event allocated one too few bytes for the row buffer.
       (Bug #15890178)

     * For the LooseScan semi-join strategy, the optimizer could rely
       on an uninitialized variable. (Bug #15849654)

     * For debug builds, an assertion could be raised when: 1) A view
       was based on a MEMORY table; 2) The table was altered to drop
       some column in use by the view; 3) A SELECT was done on the
       view with binary logging disabled. (Bug #15847447)

     * If loose index scan was used on a query with descending order,
       the result set contained NULL values instead of the correct
       values. (Bug #15848665)

     * The optimizer's cost-based choice between IN -> EXISTS
       subquery transformation and subquery materialization was
       sometimes incorrect if the IN predicate was OR-ed with some
       other predicate. (Bug #15866339)
       References: See also Bug #13111584.

     * In some cases, a cost value was printed to Optimizer Trace
       output without being initialized, resulting in incorrect
       output. (Bug #15877453)

     * Several code issues identified by Fortify were corrected. (Bug
       #15884324)

     * Some queries, if used as prepared statements, caused the
       server to exit if an error occurred. (Bug #15877062)

     * Complex IN subqueries could cause the server to exit. (Bug
       #15877738)

     * It was possible to expire the password for an account even if
       the account is authenticated by an authentication plugin that
       does not support password expiration. (Bug #15849009)

     * When the server reads the mysql.user table, it now checks for
       invalid native and old-native password hashes and ignores
       accounts with invalid hashes. (Bug #14845445)

     * The validate_password plugin did not check certain passwords.
       (Bug #14843970)

     * GRANT ... IDENTIFIED BY could fail to flush the privileges.
       (Bug #14849959)

     * Setting the validate_password_length system variable did not
       take into account that the minimum value is a function of
       several other related system variables. Now the server will
       not set the value less than the value of this expression:
validate_password_number_count
+ validate_password_special_char_count
+ (2 * validate_password_mixed_case_count)
       (Bug #14850601)

     * When used with an XPath expression that contained the output
       of a stored function, ExtractValue() failed with the error
       Only constant XPATH queries are supported. (Bug #14798445, Bug
       #67313)

     * MySQL could encounter an error during shutdown on Windows XP
       or earlier systems. This issue did not affect systems running
       Windows Vista or higher, which use atomic condition variables
       to represent Windows Events. (Bug #14822849)

     * Temporary table creation during execution of
       INFORMATION_SCHEMA queries could result in Valgrind warnings.
       (Bug #14801497)

     * mysqladmin did not properly process commands for users with
       expired passwords. (Bug #14833621)

     * XA START had a race condition that could cause a server crash.
       (Bug #14729757)

     * The server could halt with an assertion error due to a
       recently added error code:
InnoDB: unknown error code 1502
InnoDB: Assertion failure in thread thread_num in file row0mysql.cc l
ine 683
mysqld got signal 6 ;
       Now, the server returns the error code DB_DICT_CHANGED to the
       client in this case. (Bug #14764015)

     * Queries that used grouping failed when executed using a cursor
       if the optimizer processed the grouping using a temporary
       table. (Bug #14740889)

     * The server could exit when the MyISAM storage engine (rather
       than MEMORY) was used to materialize a derived table. (Bug
       #14728469)

     * The sha256_password authentication plugin requires that the
       client connect either using SSL or have RSA enabled. When
       neither condition was met, an uninformative error message was
       produced. Now the error message is more informative. (Bug
       #14751925)

     * The server now logs warnings at startup if the file specified
       for the validate_password_dictionary_file system variable
       violates constraints on valid password file contents. (Bug
       #14588148)

     * At startup, some InnoDB boolean system variables could be set
       to 1 or 0, but not ON or OFF. These included
       innodb_file_per_table, innodb_force_load_corrupted, and
       innodb_large_prefix. (Bug #14494893)

     * Output generated with mysqldump --routines could produce
       syntax errors when reloaded. (Bug #14463669)

     * Calculations involving self-intersecting polygons caused an
       assertion to be raised. (Bug #14503584)

     * If ALTER TABLE was killed, the server could report
       ER_QUERY_INTERRUPTED even if the alterations had been made
       successfully. This is misleading to the user. Also, the
       statement would not be written to the binary log, leading to
       incorrect replication (Bug #14382643)

     * The parser failed to return an error for some invalid UNION
       constructs. (Bug #13992148)

     * Preloading of client plugins specified with the
       LIBMYSQL_PLUGINS environment variable could fail unless the
       plugins were located in the hardwired default plugin
       directory. The C API now checks during plugin preloading for a
       LIBMYSQL_PLUGIN_DIR environment variable which can be set to
       the path name of the directory in which to look for client
       plugins.
       In addition, for explicit client plugin loading, the
       mysql_load_plugin() and mysql_load_plugin_v() C API functions
       have been modified to use the LIBMYSQL_PLUGIN_DIR value if it
       exists and the --plugin-dir option was not given. If
       --plugin-dir is given, mysql_load_plugin() and
       mysql_load_plugin_v() ignore LIBMYSQL_PLUGIN_DIR. (Bug
       #13994567)

     * With the ONLY_FULL_GROUP_BY SQL mode enabled, executing a
       stored function twice that contains a SQL query that is not
       valid with that mode enabled caused the server to exit. (Bug
       #13996639)

     * Autosizing of Performance Schema parameters could result in
       settings that caused excessive CPU use. (Bug #67736, Bug
       #15927744)

     * The optimizer sometimes chose a nonoptimimal range scan
       strategy when a query included a LIMIT clause. (Bug #67432,
       Bug #15829358)

     * Full-text searches in InnoDB tables could return incorrect
       results. (Bug #67257, Bug #14771282)

     * The mysql client could mishandle the delimiter command if it
       occurred on a line during which mysql was looking for the end
       of a quoted string. (Bug #64135, Bug #13639125)

     * The Performance Schema normally ignores temporary table
       events, but sometimes failed to properly identify a table as
       temporary and consequently recorded events for the table. (Bug
       #67098, Bug #14756887)

     * Some messages written by the server to the error log referred
       to the deprecated --log-slow-queries option rather than the
       --slow-query-log option. Similarly, the server referred to the
       deprecated --log option rather than the --general-log-file and
       --log-output options. (Bug #67892, Bug #15996571)

     * Attempting to perform an in-place upgrade from MySQL 5.1 to
       5.6 causes the server to exit due to a mismatch between the
       privilege structures in the two series. (This is not a
       supported operation, but the server should not exit
       ungracefully.) (Bug #67319, Bug #14826854)

     * DECIMAL multiplication operations could produce significant
       inaccuracy. (Bug #45860, Bug #11754279)

     * Due to a thread race condition, the server could exit while
       attempting to read the Performance Schema
       threads.PROCESSLIST_INFO column. (Bug #68127, Bug #16196158)

     * The optimizer could choose an IN-to-EXISTS transformation for
       subquery execution in some cases when subquery materialization
       would be cheaper. (Bug #67511, Bug #15848521)

     * It is not permitted to use CREATE TABLE to create an NDB table
       with user-defined partitioning and a foreign key. However, it
       was possible to create an NDB table with a foreign key, then
       add partitioning to it using ALTER TABLE, thus creating a
       table which was impossible to backup/restore using mysqldump.
       Now the prohibition is enforced consistently. (Bug #67492, Bug
       #15844519)

     * For single-table DELETE or UPDATE statements, EXPLAIN
       displayed a type value of ALL (full-table scan access method)
       even if the optimizer chose to scan the table by an index
       access method. Now the type value is displayed as index. (Bug
       #67637, Bug #15892875)

==============================================================================

Bugs Fixed

  * Insert operations could fail if the inserted values contained
    any bit fields, mapped to table columns declared as bit(1):

      Data too long for column 'column_name'

    (Bug #15997361, Bug #67702)

  * The is_minimum_version function could return an incorrect
    result in some cases where the difference was in the third
    component of the release number. (Bug #15926340)

  * An application making extensive use of prepared statements
    could encounter an error:

      Can't create more than max_prepared_stmt_count statements
      (current value: 16382)

    The issue occurred even if SQLFreeStmt() calls were used. The
    Prepared_stmt_count value grew until it exceeded the internal
    limit. A workaround was to disable server-side prepared
    statements. (Bug #14812778, Bug #67340)

  * On a 64-bit system, calls to the SQLBindCol function using
    indicator variables (through the last parameter) could return
    incorrect results. (Bug #11766437, Bug #59541)

Built against the MySQL server 5.5.27 client library.

     * Performance: InnoDB: The timing values for low-level InnoDB
       read operations were adjusted for better performance with fast
       storage devices, such as SSD
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_ssd
       ). This enhancement primarily affects read operations for BLOB
       columns in compressed
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_com
       pression) tables. (Bug #13702112, Bug #64258)

     * InnoDB: An online DDL operation for an InnoDB table
       incorrectly reported an empty value ('') instead of the
       correct key value when it reported a duplicate key error for a
       unique index using an index prefix. (Bug #14729221)

     * InnoDB: If a CREATE TABLE statement failed due to a disk full
       error, some memory allocated during the operation was not
       freed properly. (Bug #14708715)

     * InnoDB: If the server crashed at the specific point when a
       change buffer
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_cha
       nge_buffer) entry was being merged into a buffer pool page,
       the transaction log and the change buffer were left in an
       inconsistent state. After a restart, MySQL could crash after
       reading the corresponding secondary index page. The problem
       was more likely to occur in MySQL 5.5 or later, where the
       original insert buffering
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_ins
       ert_buffering) mechanism was generalized to cover other
       operations. (Bug #14636528, Bug #66819, Bug #58571, Bug
       #61104, Bug #65443)

     * InnoDB: In rare circumstances, MySQL could apply InnoDB undo
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_und
       o) records out of order during a ROLLBACK
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_rol
       lback) of an operation that modified a BLOB column. This issue
       could cause an assertion error in debug builds:
       !bpage->file_page_was_freed
       (Bug #13249921)

     * Replication: Updates writing user variables whose values were
       never set on a slave while using --replicate-ignore-table
       could cause the slave to fail. (Bug #14597605)
       References: This bug was introduced by Bug #14275000.

     * Replication: Backtick (`) characters were not always handled
       correctly in internally generated SQL statements, which could
       sometimes lead to errors on the slave. (Bug #14548159)

     * Replication: Following an insert into a nontransactional table
       that failed due to insufficient disk space, the server did not
       properly clean up all pending events, leading to an assert or
       possibly to other errors. (Bug #11750014)

     * Very long database names in queries could cause the server to
       exit. (Bug #15912213)

     * Within a stored procedure, executing a multiple-table DELETE
       statement that used a very long table alias could cause the
       server to exit. (Bug #15954896)

     * Attempting to create an auto-increment
       (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_aut
       o_increment) column in an InnoDB table with a NULL type
       attribute could cause a serious error. (Bug #14758479)

     * A DELETE statement for an InnoDB table could write incorrect
       transaction metadata into a record, causing the server to halt
       with an error. To work around this issue, reduce the specified
       length of the primary key to less than 1K bytes. (Bug
       #14731482)

     * Repeated execution of a query containing a subquery that used
       MAX() could result in increasing memory consumption. (Bug
       #14683676)

     * USE dbname could fail with Unknown database when dbname
       contained multiple backtick (`) characters. (Bug #14645196)

     * SHOW PROFILE could be used to cause excessive server memory
       consumption. (Bug #14629232)

     * The thread cache implementation worked in LIFO rather than
       FIFO fashion and could result in a thread being denied service
       (although this was a remote possibility). (Bug #14621627)

     * CREATE USER and DROP USER could fail to flush the privileges,
       requiring FLUSH PRIVILEGES to be used explicitly. (Bug
       #13864642)

     * A memory leak could occur for queries containing a subquery
       that used GROUP BY on an outer column. (Bug #13724099)

     * The number of connection errors from a given host as counted
       by the server was periodically reset, with the result that
       max_connect_errors was never reached and invalid hosts were
       never blocked from trying to connect. (Bug #11753779)
       References: See also Bug #38247, Bug #43006, Bug #45584, Bug
       #45606.

     * During optimization, ZEROFILL values may be converted to
       string constants. However, CASE expressions did not handle
       switching data types after the planning stage, leading to CASE
       finding a null pointer instead of its argument. (Bug #57135,
       Bug #11764313)

     * On Windows, the Perl version of mysql_install_db created
       system tables in the mysql database that were not populated
       properly. (Bug #65584, Bug #14181049)

     * mysqld_safe ignored the value of the UMASK environment
       variable, leading to behavior different from mysqld with
       respect to the access mode of created files. Now mysqld_safe
       (and mysqld_multi) attempt to approximate the same behavior as
       mysqld. (Bug #57406, Bug #11764559)

     * LAST_INSERT_ID(expr) did not work for expr values greater than
       the largest signed BIGINT value. (Bug #20964, Bug #11745891)