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https://dev.mysql.com/doc/refman/8.4/en/performance-schema-objects-summary-global-by-type-table.html
Example object wait event summary information: mysql> SELECT * FROM performance_schema.objects_summary_global_by_type\G ... The Performance Schema maintains the objects_summary_global_by_type table for aggregating object wait events. row ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-optimization.html
row *************************** id: 1 select_type: SIMPLE table: accounts partitions: NULL type: const possible_keys: ACCOUNT key: ACCOUNT key_len: 278 ref: const,const rows: 1 filtered: 100.00 Extra: NULL The EXPLAIN output indicates that the ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-performance-timers-table.html
For an explanation of how event timing occurs, see Section 29.4.1, “Performance Schema Event Timing”. For a cycle timer, the frequency is generally related to the CPU speed. For example, on a system with a 2.4GHz processor, the CYCLE may be ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-group-communication-information-table.html
If a single consensus leader is in use for the group, and the primary is currently unhealthy, the group communication selects an alternative consensus leader. This table shows group configuration options for the whole replication group. The ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-restrictions.html
For example, if you select events from a performance_schema table into a temporary table, intending to join that table with the original table later, there might be no matches. The Performance Schema avoids using mutexes to collect or produce data, ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-runtime-configuration.html
Specific Performance Schema features can be enabled at runtime to control which types of event collection occur. If you have the UPDATE privilege, you can change Performance Schema operation by modifying setup tables to affect how monitoring occurs. For additional details about these tables, see Section 29.12.2, “Performance Schema Setup ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-setup-consumers-table.html
For detailed information about the effect of enabling different consumers, see Section 29.4.7, “Pre-Filtering by Consumer”. If you disable a consumer, the server does not spend time adding event information to it. The setup_consumers table has ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-setup-instruments-table.html
The setup_instruments table lists classes of instrumented objects for which events can be collected: mysql> SELECT * FROM performance_schema.setup_instruments\G *************************** 1. row *************************** NAME: ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-setup-meters-table.html
This column can be modified DESCRIPTION: A string describing the meter.
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-setup-metrics-table.html
The setup_metrics table lists the available metrics: mysql> select * from performance_schema.setup_metrics\G *************************** 34. row *************************** NAME: undo_tablespaces_active METER: mysql.inno METRIC_TYPE: ASYNC GAUGE ...