https://dev.mysql.com/performance-schema-instrument-naming.html
This component also determines which event timer in the performance_timers table applies to the instrument. The TIMED column for the error row in the setup_instruments table is inapplicable because timing information is not collected. Memory ... An ...
https://dev.mysql.com/performance-schema-system-variables.html
This occurs even if the new statement wait time is less than that of the current sample statement. 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 ...
https://dev.mysql.com/performance-timers-table.html
For a cycle timer, the frequency is generally related to the CPU speed. TIMER_RESOLUTION Indicates the number of timer units by which timer values increase. If a timer has a resolution of 10, its value increases by 10 each time. TIMER_OVERHEAD The ...For an explanation of how event timing occurs, see Section 26.4.1, “Performance Schema Event ...
https://dev.mysql.com/replication-gtids-failover.html
This method is simple and effective, but requires the slave to read the binary log from the master; it can sometimes take a comparatively long time for the new slave to catch up with the master, so this method is not suitable for fast failover or ...
https://dev.mysql.com/show-slave-status.html
This means that there is a small window of time during which SHOW SLAVE STATUS shows a nonzero value for Last_SQL_Errno even though Slave_SQL_Running still displays Yes. Seconds_Behind_Master This field is an indication of how “late” the slave ... SHOW SLAVE STATUS [FOR CHANNEL channel] This statement provides status information on essential parameters of the slave ...
https://dev.mysql.com/show-table-status.html
For example, InnoDB stores multiple tables in its system tablespace and the data file timestamp does not apply. Even with file-per-table mode with each InnoDB table in a separate .ibd file, change buffering can delay the write to the data file, so ... SHOW TABLE STATUS [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW TABLE STATUS works likes SHOW TABLES, but provides a lot of information about each non-TEMPORARY ...
https://dev.mysql.com/socket-instances-table.html
The socket_instances table provides a real-time snapshot of the active connections to the MySQL server. Information available in this table provides a real-time snapshot of the active connections to the server. Wait times for active sockets are ...
https://dev.mysql.com/stored-program-restrictions.html
If you refer to a temporary table multiple times in a stored function under different aliases, a Can't reopen table: 'tbl_name' error occurs, even if the references occur in different statements within the function. In addition—due to rounding, ...
https://dev.mysql.com/sys-host-summary-by-statement-latency.html
total_latency The total wait time of timed statements for the host. max_latency The maximum single wait time of timed statements for the host. lock_latency The total time waiting for locks by timed statements for the host. The ...
https://dev.mysql.com/sys-host-summary-by-statement-type.html
total_latency The total wait time of timed occurrences of the statement event for the host. max_latency The maximum single wait time of timed occurrences of the statement event for the host. lock_latency The total time waiting for locks by timed ...
