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https://dev.mysql.com/doc/refman/8.0/en/sys-waits-global-by-latency.html
The waits_global_by_latency and x$waits_global_by_latency views have these columns: events The event name. total_latency The total wait time of timed occurrences of the event. avg_latency The average wait time per timed occurrence of the event.
https://dev.mysql.com/doc/refman/8.0/en/table-scan-avoidance.html
The output from EXPLAIN shows ALL in the type column when MySQL uses a full table scan to resolve a query. This usually happens under the following conditions: The table is so small that it is faster to perform a table scan than to bother with a ...
https://dev.mysql.com/doc/refman/8.0/en/table.html
TABLE is a DML statement introduced in MySQL 8.0.19 which returns rows and columns of the named table. Given the existence of a table named t, the following two statements produce identical output: TABLE t; SELECT * FROM t; You can order and limit ...
https://dev.mysql.com/doc/refman/8.0/en/temporary-table-problems.html
Temporary tables created with CREATE TEMPORARY TABLE have the following limitations: TEMPORARY tables are supported only by the InnoDB, MEMORY, MyISAM, and MERGE storage engines. Use ALTER TABLE instead: ALTER TABLE old_name RENAME new_name; You ...
https://dev.mysql.com/doc/refman/8.0/en/thread-commands.html
A thread can have any of the following Command values: Binlog Dump This is a thread on a replication source for sending binary log contents to a replica. Connect Used by replication receiver threads connected to the source, and by replication ...
https://dev.mysql.com/doc/refman/8.0/en/thread-pool-tuning.html
Higher values tend to have a slightly negative but not dramatic impact on performance. This section provides guidelines on determining the best configuration for thread pool performance, as measured using a metric such as transactions per second.
https://dev.mysql.com/doc/refman/8.0/en/too-many-connections.html
The extra connection is reserved for use by accounts that have the CONNECTION_ADMIN privilege (or the deprecated SUPER privilege). If clients encounter Too many connections errors when attempting to connect to the mysqld server, all available ...
https://dev.mysql.com/doc/refman/8.0/en/triggers.html
For example, you can have a trigger activate before each row that is inserted into a table or after each row that is updated. A trigger is a named database object that is associated with a table, and that activates when a particular event occurs ...
https://dev.mysql.com/doc/refman/8.0/en/tuning-trace-purging.html
A stored routine may have a loop which executes many substatements and thus generates many traces, which can use a lot of memory; in such cases, choosing appropriate values for offset and limit can restrict tracing to, for example, a single ...Thus, ...
https://dev.mysql.com/doc/refman/8.0/en/type-conversion.html
If the two values have the same JSON type, a second level of comparison occurs using type-specific rules. When an operator is used with operands of different types, type conversion occurs to make the operands compatible. For example, MySQL ...