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https://dev.mysql.com/doc/refman/8.4/en/group-replication-single-primary-mode.html
20.1.3.1.2 Finding the Primary To find out which server is currently the primary when deployed in single-primary mode, use the MEMBER_ROLE column in the performance_schema.replication_group_members table. In single-primary mode ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-keywords-table.html
The KEYWORDS table lists the words considered keywords by MySQL and, for each one, indicates whether it is reserved. Reserved keywords may require special treatment in some contexts, such as special quoting when used as identifiers (see Section ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-redo-log.html
The following query retrieves data from all of the table's columns: SELECT FILE_ID, START_LSN, END_LSN, SIZE_IN_BYTES, IS_FULL, CONSUMER_LEVEL FROM performance_schema.innodb_redo_log_files; Automatic Redo Log Capacity Configuration When the server ... The redo log is a disk-based data structure used during crash recovery to correct data written by incomplete ...
https://dev.mysql.com/doc/refman/8.4/en/monitor-innodb-mutex-waits-performance-schema.html
The ENABLED and TIMED columns should be set to YES for the instruments that you enabled. $> ./mysqlslap --auto-generate-sql --concurrency=100 --iterations=10 --number-of-queries=1000 --number-char-cols=6 --number-int-cols=6; Query the wait event ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-hints.html
If DUPSWEEDOUT is disabled, on occasion the optimizer may generate a query plan that is far from optimal. One means of control over optimizer strategies is to set the optimizer_switch system variable (see Section 10.9.2, “Switchable ...
https://dev.mysql.com/doc/refman/8.4/en/outer-join-simplification.html
(That is, it converts the outer join to an inner join.) A condition is said to be null-rejected for an outer join operation if it evaluates to FALSE or UNKNOWN for any NULL-complemented row generated for the operation. Table expressions in the FROM ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-stages-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_stages_history_long table contains the N most recent stage events that have ended globally, across all ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-statements-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_statements_history_long table contains the N most recent statement events that have ended globally, across ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-transactions-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_transactions_history_long table contains the N most recent transaction events that have ended globally, ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-waits-history-long-table.html
When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The events_waits_history_long table contains N the most recent wait events that have ended globally, across all ...