Documentation Home
MySQL 8.4 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 39.8Mb
PDF (A4) - 39.9Mb
Man Pages (TGZ) - 257.9Kb
Man Pages (Zip) - 364.9Kb
Info (Gzip) - 4.0Mb
Info (Zip) - 4.0Mb


29.12.3.1 cond_instances 表

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 that a thread waiting for this condition can resume work.

When a thread is waiting for something to happen, the condition name is an indication of what the thread is waiting for, but there is no immediate way to tell which other thread, or threads, causes the condition to happen.

The cond_instances table has these columns:

  • NAME

    The instrument name associated with the condition.

  • OBJECT_INSTANCE_BEGIN

    The address in memory of the instrumented condition.

The cond_instances table has these indexes:

  • Primary key on (OBJECT_INSTANCE_BEGIN)

  • Index on (NAME)

TRUNCATE TABLE is not permitted for the cond_instances table.