7.27 Performance Schema Configuration Metrics

Lists the Performance Schema configuration metrics and provides a brief description of each.

Table 7.27 Performance Schema Configuration Metrics

Name	Description
Accounts Size	The number of rows in the accounts table.
Digests Size	The maximum number of rows in the events_statements_summary_by_digest table.
Enabled	The value of this variable is ON or OFF to indicate whether the Performance Schema is enabled. By default, the value is OFF. At server startup, you can specify this variable with no value or a value of 1 to enable it, or with a value of 0 to disable it.
Error Size	The number of instrumented server error codes. By default all errors are instrumented.
Events Stages History Long Size	The number of rows in the events_stages_history_long table.
Events Stages History Size	The number of rows in the events_stages_history table.
Events Statements History Long Size	The number of rows in the events_statements_history_long table.
Events Statements History Size	The number of rows in the events_statements_history table.
Events Transactions History Long Size	The number of rows in the events_transactions_history_long table.
Events Transactions History Size	The number of rows per thread in the events_transactions_history table.
Events Waits History Long Size	The number of rows in the events_waits_history_long table.
Events Waits History Size	The number of rows per thread in the events_waits_history table.
Hosts Size	The number of rows in the hosts table.
Max Cond Classes	The maximum number of condition instruments.
Max Cond Instances	The maximum number of instrumented condition objects.
Max Digest Length	The maximum number of bytes available for computing statement digests.
Max Digest Sample Age	The query resample age (in seconds) for the events_statements_summary_by_digest table. Default value is 60 seconds.
Max File Classes	The maximum number of file instruments.
Max File Handles	The maximum number of opened file objects. The value of performance_schema_max_file_handles should be greater than the value of open_files_limit: open_files_limit affects the maximum number of open file handles the server can support and performance_schema_max_file_handles affects how many of these file handles can be instrumented.
Max File Instances	The maximum number of instrumented file objects.
Max Index Stat	The maximum number of indexes for which the Performance Schema maintains statistics.
Max Memory Classes	The maximum number of memory instruments.
Max Metadata Locks	The maximum number of metadata lock instruments.
Max Mutex Classes	The maximum number of mutex instruments.
Max Mutex Instances	The maximum number of instrumented mutex objects.
Max Prepared Statements Instances	The maximum number of rows in the prepared_statements_instances table.
Max Program Instances	The maximum number of stored programs for which the Performance Schema maintains statistics.
Max Rwlock Classes	The maximum number of rwlock instruments.
Max Rwlock Instances	The maximum number of instrumented rwlock objects.
Max Socket Classes	The maximum number of socket instruments.
Max Socket Instances	The maximum number of instrumented socket objects.
Max SQL Text Length	The maximum number of bytes used to store SQL statements in the SQL_TEXT column of the events_statements_current, events_statements_history, and events_statements_history_long statement event tables.
Max Stage Classes	The maximum number of stage instruments.
Max Statement Classes	The maximum number of statement instruments. The default value is calculated at server build time based on the number of commands in the client/server protocol and the number of SQL statement types supported by the server.
Max Statement Stack	The maximum depth of nested stored program calls for which the Performance Schema maintains statistics.
Max Table Handles	The maximum number of opened table objects.
Max Table Instances	The maximum number of instrumented table objects.
Max Table Lock Stat	The maximum number of tables for which the Performance Schema maintains lock statistics.
Max Thread Classes	The maximum number of thread instruments.
Max Thread Instances	The maximum number of instrumented thread objects. The max_connections and max_delayed_threads system variables affect how many threads are run in the server. performance_schema_max_thread_instances affects how many of these running threads can be instrumented. If you increase max_connections or max_delayed_threads, consider increasing performance_schema_max_thread_instances so that performance_schema_max_thread_instances is greater than the sum of max_connections and max_delayed_threads.
Session Connect Attrs Size	The amount of preallocated memory per thread used to hold connection attribute strings.
Setup Actors Size	The number of rows in the setup_actors table.
Setup Objects Size	The number of rows in the setup_objects table.
Users Size	The number of rows in the users table.