Re: Optimized Indexing for a Schedule Table

[Wes Thompson]

I'm using MySQL 5.0.51a on a Debian box. I may move to 5.1 b/c the SELECT syntax added clauses like "...USE INDEX(..) FOR ORDER BY.." which may help improve performance.

I set innodb_buffer_pool_size = 128M and restarted the daemon. There was a performance improvement. Instead of query time getting higher for higher prio, it increased and then leveled off. I also saw improvements in other InnoDb table queries.

$ mysql -V
mysql Ver 14.12 Distrib 5.0.51a, for debian-linux-gnu (i486) using readline 5.2

mysql> show global status;
+-----------------------------------+-----------+
| Variable_name | Value |
+-----------------------------------+-----------+
| Aborted_clients | 0 |
| Aborted_connects | 0 |
| Binlog_cache_disk_use | 0 |
| Binlog_cache_use | 0 |
| Bytes_received | 397650 |
| Bytes_sent | 249156 |
| Com_admin_commands | 2 |
| Com_alter_db | 0 |
| Com_alter_table | 0 |
| Com_analyze | 0 |
| Com_backup_table | 0 |
| Com_begin | 0 |
| Com_call_procedure | 0 |
| Com_change_db | 1 |
| Com_change_master | 0 |
| Com_check | 0 |
| Com_checksum | 0 |
| Com_commit | 154 |
| Com_create_db | 0 |
| Com_create_function | 0 |
| Com_create_index | 0 |
| Com_create_table | 0 |
| Com_create_user | 0 |
| Com_dealloc_sql | 0 |
| Com_delete | 0 |
| Com_delete_multi | 0 |
| Com_do | 0 |
| Com_drop_db | 0 |
| Com_drop_function | 0 |
| Com_drop_index | 0 |
| Com_drop_table | 0 |
| Com_drop_user | 0 |
| Com_execute_sql | 0 |
| Com_flush | 0 |
| Com_grant | 0 |
| Com_ha_close | 0 |
| Com_ha_open | 0 |
| Com_ha_read | 0 |
| Com_help | 0 |
| Com_insert | 1187 |
| Com_insert_select | 0 |
| Com_kill | 0 |
| Com_load | 0 |
| Com_load_master_data | 0 |
| Com_load_master_table | 0 |
| Com_lock_tables | 0 |
| Com_optimize | 0 |
| Com_preload_keys | 0 |
| Com_prepare_sql | 0 |
| Com_purge | 0 |
| Com_purge_before_date | 0 |
| Com_rename_table | 0 |
| Com_repair | 0 |
| Com_replace | 0 |
| Com_replace_select | 0 |
| Com_reset | 0 |
| Com_restore_table | 0 |
| Com_revoke | 0 |
| Com_revoke_all | 0 |
| Com_rollback | 0 |
| Com_savepoint | 0 |
| Com_select | 441 |
| Com_set_option | 312 |
| Com_show_binlog_events | 0 |
| Com_show_binlogs | 0 |
| Com_show_charsets | 0 |
| Com_show_collations | 0 |
| Com_show_column_types | 0 |
| Com_show_create_db | 0 |
| Com_show_create_table | 0 |
| Com_show_databases | 1 |
| Com_show_errors | 0 |
| Com_show_fields | 2 |
| Com_show_grants | 0 |
| Com_show_innodb_status | 0 |
| Com_show_keys | 0 |
| Com_show_logs | 0 |
| Com_show_master_status | 0 |
| Com_show_ndb_status | 0 |
| Com_show_new_master | 0 |
| Com_show_open_tables | 0 |
| Com_show_privileges | 0 |
| Com_show_processlist | 0 |
| Com_show_slave_hosts | 0 |
| Com_show_slave_status | 0 |
| Com_show_status | 3 |
| Com_show_storage_engines | 0 |
| Com_show_tables | 2 |
| Com_show_triggers | 0 |
| Com_show_variables | 2 |
| Com_show_warnings | 0 |
| Com_slave_start | 0 |
| Com_slave_stop | 0 |
| Com_stmt_close | 0 |
| Com_stmt_execute | 0 |
| Com_stmt_fetch | 0 |
| Com_stmt_prepare | 0 |
| Com_stmt_reset | 0 |
| Com_stmt_send_long_data | 0 |
| Com_truncate | 0 |
| Com_unlock_tables | 0 |
| Com_update | 752 |
| Com_update_multi | 0 |
| Com_xa_commit | 0 |
| Com_xa_end | 0 |
| Com_xa_prepare | 0 |
| Com_xa_recover | 0 |
| Com_xa_rollback | 0 |
| Com_xa_start | 0 |
| Compression | OFF |
| Connections | 168 |
| Created_tmp_disk_tables | 24 |
| Created_tmp_files | 5 |
| Created_tmp_tables | 109 |
| Delayed_errors | 0 |
| Delayed_insert_threads | 0 |
| Delayed_writes | 0 |
| Flush_commands | 1 |
| Handler_commit | 2093 |
| Handler_delete | 0 |
| Handler_discover | 0 |
| Handler_prepare | 0 |
| Handler_read_first | 7 |
| Handler_read_key | 4806 |
| Handler_read_next | 9279344 |
| Handler_read_prev | 0 |
| Handler_read_rnd | 0 |
| Handler_read_rnd_next | 4656 |
| Handler_rollback | 0 |
| Handler_savepoint | 0 |
| Handler_savepoint_rollback | 0 |
| Handler_update | 0 |
| Handler_write | 5792 |
| Innodb_buffer_pool_pages_data | 6779 |
| Innodb_buffer_pool_pages_dirty | 67 |
| Innodb_buffer_pool_pages_flushed | 903 |
| Innodb_buffer_pool_pages_free | 1295 |
| Innodb_buffer_pool_pages_latched | 4 |
| Innodb_buffer_pool_pages_misc | 118 |
| Innodb_buffer_pool_pages_total | 8192 |
| Innodb_buffer_pool_read_ahead_rnd | 4 |
| Innodb_buffer_pool_read_ahead_seq | 67 |
| Innodb_buffer_pool_read_requests | 1375356 |
| Innodb_buffer_pool_reads | 2787 |
| Innodb_buffer_pool_wait_free | 0 |
| Innodb_buffer_pool_write_requests | 16162 |
| Innodb_data_fsyncs | 1194 |
| Innodb_data_pending_fsyncs | 0 |
| Innodb_data_pending_reads | 1 |
| Innodb_data_pending_writes | 0 |
| Innodb_data_read | 113037312 |
| Innodb_data_reads | 3003 |
| Innodb_data_writes | 1807 |
| Innodb_data_written | 30768640 |
| Innodb_dblwr_pages_written | 903 |
| Innodb_dblwr_writes | 21 |
| Innodb_log_waits | 0 |
| Innodb_log_write_requests | 1207 |
| Innodb_log_writes | 1138 |
| Innodb_os_log_fsyncs | 1152 |
| Innodb_os_log_pending_fsyncs | 0 |
| Innodb_os_log_pending_writes | 0 |
| Innodb_os_log_written | 1171968 |
| Innodb_page_size | 16384 |
| Innodb_pages_created | 13 |
| Innodb_pages_read | 6765 |
| Innodb_pages_written | 903 |
| Innodb_row_lock_current_waits | 0 |
| Innodb_row_lock_time | 0 |
| Innodb_row_lock_time_avg | 0 |
| Innodb_row_lock_time_max | 0 |
| Innodb_row_lock_waits | 0 |
| Innodb_rows_deleted | 0 |
| Innodb_rows_inserted | 0 |
| Innodb_rows_read | 9282019 |
| Innodb_rows_updated | 1939 |
| Key_blocks_not_flushed | 0 |
| Key_blocks_unused | 14497 |
| Key_blocks_used | 0 |
| Key_read_requests | 0 |
| Key_reads | 0 |
| Key_write_requests | 0 |
| Key_writes | 0 |
| Last_query_cost | 0.000000 |
| Max_used_connections | 4 |
| Ndb_cluster_node_id | 0 |
| Ndb_config_from_host | |
| Ndb_config_from_port | 0 |
| Ndb_number_of_data_nodes | 0 |
| Not_flushed_delayed_rows | 0 |
| Open_files | 116 |
| Open_streams | 0 |
| Open_tables | 64 |
| Opened_tables | 1035 |
| Prepared_stmt_count | 0 |
| Qcache_free_blocks | 1 |
| Qcache_free_memory | 16655824 |
| Qcache_hits | 931 |
| Qcache_inserts | 108 |
| Qcache_lowmem_prunes | 0 |
| Qcache_not_cached | 341 |
| Qcache_queries_in_cache | 108 |
| Qcache_total_blocks | 218 |
| Questions | 3952 |
| Rpl_status | NULL |
| Select_full_join | 0 |
| Select_full_range_join | 0 |
| Select_range | 2 |
| Select_range_check | 0 |
| Select_scan | 16 |
| Slave_open_temp_tables | 0 |
| Slave_retried_transactions | 0 |
| Slave_running | OFF |
| Slow_launch_threads | 0 |
| Slow_queries | 0 |
| Sort_merge_passes | 0 |
| Sort_range | 2 |
| Sort_rows | 0 |
| Sort_scan | 0 |
| Ssl_accept_renegotiates | 0 |
| Ssl_accepts | 0 |
| Ssl_callback_cache_hits | 0 |
| Ssl_cipher | |
| Ssl_cipher_list | |
| Ssl_client_connects | 0 |
| Ssl_connect_renegotiates | 0 |
| Ssl_ctx_verify_depth | 0 |
| Ssl_ctx_verify_mode | 0 |
| Ssl_default_timeout | 0 |
| Ssl_finished_accepts | 0 |
| Ssl_finished_connects | 0 |
| Ssl_session_cache_hits | 0 |
| Ssl_session_cache_misses | 0 |
| Ssl_session_cache_mode | NONE |
| Ssl_session_cache_overflows | 0 |
| Ssl_session_cache_size | 0 |
| Ssl_session_cache_timeouts | 0 |
| Ssl_sessions_reused | 0 |
| Ssl_used_session_cache_entries | 0 |
| Ssl_verify_depth | 0 |
| Ssl_verify_mode | 0 |
| Ssl_version | |
| Table_locks_immediate | 2227 |
| Table_locks_waited | 0 |
| Tc_log_max_pages_used | 0 |
| Tc_log_page_size | 0 |
| Tc_log_page_waits | 0 |
| Threads_cached | 0 |
| Threads_connected | 4 |
| Threads_created | 4 |
| Threads_running | 2 |
| Uptime | 339 |
| Uptime_since_flush_status | 339 |
+-----------------------------------+-----------+
253 rows in set (0.01 sec)