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MySQL Performance Schema  /  Performance Schema Table Descriptions

Chapter 10 Performance Schema Table Descriptions

Table of Contents

10.1 Performance Schema Table Reference
10.2 Performance Schema Setup Tables
10.2.1 The setup_actors Table
10.2.2 The setup_consumers Table
10.2.3 The setup_instruments Table
10.2.4 The setup_objects Table
10.2.5 The setup_timers Table
10.3 Performance Schema Instance Tables
10.3.1 The cond_instances Table
10.3.2 The file_instances Table
10.3.3 The mutex_instances Table
10.3.4 The rwlock_instances Table
10.3.5 The socket_instances Table
10.4 Performance Schema Wait Event Tables
10.4.1 The events_waits_current Table
10.4.2 The events_waits_history Table
10.4.3 The events_waits_history_long Table
10.5 Performance Schema Stage Event Tables
10.5.1 The events_stages_current Table
10.5.2 The events_stages_history Table
10.5.3 The events_stages_history_long Table
10.6 Performance Schema Statement Event Tables
10.6.1 The events_statements_current Table
10.6.2 The events_statements_history Table
10.6.3 The events_statements_history_long Table
10.7 Performance Schema Connection Tables
10.7.1 The accounts Table
10.7.2 The hosts Table
10.7.3 The users Table
10.8 Performance Schema Connection Attribute Tables
10.8.1 The session_account_connect_attrs Table
10.8.2 The session_connect_attrs Table
10.9 Performance Schema Summary Tables
10.9.1 Wait Event Summary Tables
10.9.2 Stage Summary Tables
10.9.3 Statement Summary Tables
10.9.4 Object Wait Summary Table
10.9.5 File I/O Summary Tables
10.9.6 Table I/O and Lock Wait Summary Tables
10.9.7 Socket Summary Tables
10.10 Performance Schema Miscellaneous Tables
10.10.1 The host_cache Table
10.10.2 The performance_timers Table
10.10.3 The threads Table

Tables in the performance_schema database can be grouped as follows:

  • Setup tables. These tables are used to configure and display monitoring characteristics.

  • Current events tables. The events_waits_current table contains the most recent event for each thread. Other similar tables contain current events at different levels of the event hierarchy: events_stages_current for stage events, and events_statements_current for statement events.

  • History tables. These tables have the same structure as the current events tables, but contain more rows. For example, for wait events, events_waits_history table contains the most recent 10 events per thread. events_waits_history_long contains the most recent 10,000 events. Other similar tables exist for stage and statement histories.

    To change the sizes of the history tables, set the appropriate system variables at server startup. For example, to set the sizes of the wait event history tables, set performance_schema_events_waits_history_size and performance_schema_events_waits_history_long_size.

  • Summary tables. These tables contain information aggregated over groups of events, including those that have been discarded from the history tables.

  • Instance tables. These tables document what types of objects are instrumented. An instrumented object, when used by the server, produces an event. These tables provide event names and explanatory notes or status information.

  • Miscellaneous tables. These do not fall into any of the other table groups.