The cond instances Table The cond_instances table lists all the conditions seen by the Performance Schema while the server executes. A condition is a synchronization mechanism used in the code to signal that a specific event has happened, so...
The CSV Storage Engine The CSV storage engine stores data in text files using comma-separated values format. The CSV storage engine is always compiled into the MySQL server. To examine the source for the CSV engine, look in the storage/csv directory of a MySQL source distribution. When you crea...
The EXAMPLE Storage Engine The EXAMPLE storage engine is a stub engine that does nothing. Its purpose is to serve as an example in the MySQL source code that illustrates how to begin writing new storage engines. As such, it is primarily of interest to developers. To enable the EXAMPLE storage en...
The FEDERATED Storage Engine The FEDERATED storage engine lets you access data from a remote MySQL database without using replication or cluster technology. Querying a local FEDERATED table automatically pulls the data from the remote (federated) tables. No data is stored on the local tables. To...
The file instances Table The file_instances table lists all the files seen by the Performance Schema when executing file I/O instrumentation. If a file on disk has never been opened, it will not be in file_instances. When a file is deleted f...
The MERGE Storage Engine The MERGE storage engine, also known as the MRG_MyISAM engine, is a collection of identical MyISAM tables that can be used as one. “Identical” means that all tables have identical column and index information. You cannot ...
The rwlock instances Table The rwlock_instances table lists all the rwlock instances (read write locks) seen by the Performance Schema while the server executes. An rwlock is a synchronization mechanism used in the code to enforce that threads at a given time can have access to some common resour...
The setup actors Table The setup_actors table contains information that determines whether to enable monitoring for new foreground server threads; that is, threads associated with client connections. This table has a maximum size of 100 rows by default. The size may be changed by modifying the p...
The setup objects Table The setup_objects table controls whether particular objects are monitored. This table has a maximum size of 100 rows by default. The size may be changed by modifying the performance_schema_setup_objects_size [2765] system variable at server startup. The initial setup_obje...
The setup timers Table The setup_timers table shows the currently selected event timers: mysql SELECT * FROM setup_timers; +++ | NAME | TIMER_NAME | +++ | idle | MICROSECOND | | wait | CYCLE | | stage | NANOSECOND | | statement | NANOSECOND | +++ The setup_timers table has these columns: ...
