通过performance schema收集慢查询

小程序：扫一扫查出行
【扫一扫了解最新限行尾号】
复制小程序

MySQL5.6起performance schema自动开启，里面涉及记录 statement event的表

mysql> show tables like '%statement%';
+----------------------------------------------------+
| Tables_in_performance_schema (%statement%) |
+----------------------------------------------------+
| events_statements_current |
| events_statements_history |
| events_statements_history_long |
| events_statements_summary_by_account_by_event_name |
| events_statements_summary_by_digest |
| events_statements_summary_by_host_by_event_name |
| events_statements_summary_by_program |
| events_statements_summary_by_thread_by_event_name |
| events_statements_summary_by_user_by_event_name |
| events_statements_summary_global_by_event_name |
| prepared_statements_instances |
+----------------------------------------------------+
rows in set (0.00 sec)

statement event 的设置

详细参考官方文档：https://dev.mysql.com/doc/refman/5.6/en/performance-schema-statement-tables.ht

server端发生的所有的statement都会记录，当前未结束的会话发生的statement记录在表events_statements_current，已结束的会话线程发生的statement记录在events_statements_history，此表有大小限制，默认是100，达到限制会删除老的statement

设置记录哪些类型的statement，默认设置为所有的类型

mysql> SELECT * FROM setup_instruments WHERE NAME LIKE 'statement/%';
+---------------------------------------------+---------+-------+
| NAME | ENABLED | TIMED |
+---------------------------------------------+---------+-------+
| statement/sql/select | YES | YES |
| statement/sql/create_table | YES | YES |
| statement/sql/create_index | YES | YES |
...
| statement/sp/stmt | YES | YES |
| statement/sp/set | YES | YES |
| statement/sp/set_trigger_field | YES | YES |
| statement/scheduler/event | YES | YES |
| statement/com/Sleep | YES | YES |
| statement/com/Quit | YES | YES |
| statement/com/Init DB | YES | YES |
...
| statement/abstract/Query | YES | YES |
| statement/abstract/new_packet | YES | YES |
| statement/abstract/relay_log | YES | YES |
+---------------------------------------------+---------+-------+

关于对statement event相关表的设置，MySQL5.6 默认events_statements_history关闭，MySQL5.7开启

mysql> SELECT * FROM setup_consumers WHERE NAME LIKE '%statements%';
+--------------------------------+---------+
| NAME | ENABLED |
+--------------------------------+---------+
| events_statements_current | YES |
| events_statements_history | NO |
| events_statements_history_long | NO |
| statements_digest | YES |
+--------------------------------+---------+

如果通过pmm来收集慢查询，其查询的是表events_statements_history_long，MySQL5.6需要启用此表

启用events_statements_history

UPDATE setup_consumers SET ENABLED = 'NO'
WHERE NAME LIKE 'events_statements_history';