Related Documentation Download this Excerpt
PDF (US Ltr) - 269.4Kb
PDF (A4) - 270.6Kb
HTML Download (TGZ) - 52.3Kb
HTML Download (Zip) - 70.6Kb


MySQL Performance Schema  /  Performance Schema System Variables

Chapter 12 Performance Schema System Variables

The Performance Schema implements several system variables that provide configuration information:

mysql> SHOW VARIABLES LIKE 'perf%';
+---------------------------------------------------+---------+
| Variable_name                                     | Value   |
+---------------------------------------------------+---------+
| performance_schema                                | ON      |
| performance_schema_events_waits_history_long_size | 10000   |
| performance_schema_events_waits_history_size      | 10      |
| performance_schema_max_cond_classes               | 80      |
| performance_schema_max_cond_instances             | 1000    |
| performance_schema_max_file_classes               | 50      |
| performance_schema_max_file_handles               | 32768   |
| performance_schema_max_file_instances             | 10000   |
| performance_schema_max_mutex_classes              | 200     |
| performance_schema_max_mutex_instances            | 1000000 |
| performance_schema_max_rwlock_classes             | 30      |
| performance_schema_max_rwlock_instances           | 1000000 |
| performance_schema_max_table_handles              | 100000  |
| performance_schema_max_table_instances            | 50000   |
| performance_schema_max_thread_classes             | 50      |
| performance_schema_max_thread_instances           | 1000    |
+---------------------------------------------------+---------+

Performance Schema system variables can be set at server startup on the command line or in option files, and many can be set at runtime. See Performance Schema Option and Variable Reference.

Performance Schema system variables have the following meanings:


User Comments
User comments in this section are, as the name implies, provided by MySQL users. The MySQL documentation team is not responsible for, nor do they endorse, any of the information provided here.
Sign Up Login You must be logged in to post a comment.