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https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-stages-current-table.html
The table stores one row per thread showing the current status of the thread's most recent monitored stage event, so there is no system variable for configuring the table size. Of the tables that contain stage event rows, events_stages_current is ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-transactions-current-table.html
The table stores one row per thread showing the current status of the thread's most recent monitored transaction event, so there is no system variable for configuring the table size. For example: mysql> SELECT * FROM ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-log-status-table.html
The log_status table provides information that enables an online backup tool to copy the required log files without locking those resources for the duration of the copy process. When the log_status table is queried, the server blocks logging and ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-mutex-instances-table.html
The mutex_instances table lists all the mutexes seen by the Performance Schema while the server executes. A mutex is a synchronization mechanism used in the code to enforce that only one thread at a given time can have access to some common ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-group-member-stats-table.html
The replication_group_member_stats table has these columns: CHANNEL_NAME Name of the Group Replication channel VIEW_ID Current view identifier for this group. This has a different value for each member in the group. This also serves as a key because ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-group-members-table.html
This table shows network and status information for replication group members. The network addresses shown are the addresses used to connect clients to the group, and should not be confused with the member's internal group communication address ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-socket-instances-table.html
The socket_instances table provides a real-time snapshot of the active connections to the MySQL server. The table contains one row per TCP/IP or Unix socket file connection. Information available in this table provides a real-time snapshot of the ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-statement-histogram-summary-tables.html
The Performance Schema maintains statement event summary tables that contain information about minimum, maximum, and average statement latency (see Section 29.12.20.3, “Statement Summary Tables”). To permit assessment at a more fine-grained ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-wait-summary-tables.html
The Performance Schema maintains tables for collecting current and recent wait events, and aggregates that information in summary tables. Section 29.12.4, “Performance Schema Wait Event Tables” describes the events on which wait summaries are ...
https://dev.mysql.com/doc/refman/8.4/en/primary-key-optimization.html
The primary key for a table represents the column or set of columns that you use in your most vital queries. Query performance benefits from the NOT NULL optimization, because it cannot include any NULL values. With the InnoDB storage engine, the ...