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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-options.html
Performance Schema parameters can be specified at server startup on the command line or in option files to configure Performance Schema instruments and consumers. Runtime configuration is also possible in many cases (see Section 29.4, ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-persisted-variables-table.html
The persisted_variables table provides an SQL interface to the mysqld-auto.cnf file that stores persisted global system variable settings, enabling the file contents to be inspected at runtime using SELECT statements. Variables are persisted using ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-prepared-statements-instances-table.html
The Performance Schema provides instrumentation for prepared statements, for which there are two protocols: The binary protocol. This is accessed through the MySQL C API and maps onto underlying server commands as shown in the following table. C ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-queries.html
Pre-filtering limits which event information is collected and is independent of any particular user. By contrast, post-filtering is performed by individual users through the use of queries with appropriate WHERE clauses that restrict what event ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-applier-status-table.html
This table shows the current general transaction execution status on the replica. The table provides information about general aspects of transaction applier status that are not specific to any thread involved. Thread-specific status information is ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-connection-status-table.html
This table shows the current status of the I/O thread that handles the replica's connection to the source, information on the last transaction queued in the relay log, and information on the transaction currently being queued in the relay log. It ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-tables.html
This is similar to the information available from the SHOW REPLICA STATUS statement, but representation in table form is more accessible and has usability benefits: SHOW REPLICA STATUS output is useful for visual inspection, but not so much for ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-status-monitoring.html
Names for these variables have several forms: Performance_schema_xxx_classes_lost indicates how many instruments of type xxx could not be loaded. Performance_schema_xxx_instances_lost indicates how many instances of object type xxx could not be ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-status-variable-tables.html
The MySQL server maintains many status variables that provide information about its operation (see Section 7.1.10, “Server Status Variables”). Status variable information is available in these Performance Schema tables: global_status: Global ...