Re: Drop column of big table

[Zach Ellis]

What does your error log say.

this setting mite help if it shows on the error log

innodb_online_alter_log_max_size

The operation takes a long time and concurrent DML modifies the table so much that the size of the temporary online log exceeds the value of the innodb_online_alter_log_max_size
configuration option. This condition causes a DB_ONLINE_LOG_TOO_BIG error.

don't drop the primary key skip that thought you might have secondary indexes I should have specified that.

15.12.3 Online DDL Space Requirements

Temporary log files:
A temporary log file records concurrent DML when an online DDL operation
creates an index or alters a table. The temporary log file is extended as required
by the value of innodb_sort_buffer_size up to a maximum specified by
innodb_online_alter_log_max_size. If the operation takes a long time and concurrent
DML modifies the table so much that the size of the temporary log file exceeds the value
of innodb_online_alter_log_max_size, the online DDL operation fails with a
DB_ONLINE_LOG_TOO_BIG error, and uncommitted concurrent DML operations are rolled back. A
large innodb_online_alter_log_max_size setting permits more DML during an online DDL
operation, but it also extends the period of time at the end of the DDL operation when the table is
locked to apply logged DML.
The innodb_sort_buffer_size variable also defines the size of the temporary log file read
buffer and write buffer.

if your getting the DB_ONLINE_LOG_TOO_BIG error increasing the innodb_online_alter_log_max_size might help but if im reading it right it says it will increase the time but it might not crash if set accordingly.