Category Archives: Sys Schema

Extending the SYS schema to show metadata locks

Starting with MySQL 5.7, performance_schema has been enhanced to instrument metadata locks, and can be turned on by adding the following line to your my.cnf file:

(At runtime, it can also be enabled by modifying the setup_instruments table in performance_schema.)

From here, you can now query performance_schema.metadata_locks to reveal all currently open metadata locks on your server:

The MySQL SYS Schema in MySQL 5.7.7

New in MySQL 5.7.7, the MySQL sys schema (originally the ps_helper project) is now included by default within the MySQL server!

For those unfamiliar with the sys schema project, it is a database schema¬†with a set of objects (views, stored procedures, stored functions, and table with a couple of triggers on it) that were¬†implemented to give easy,¬†human readable, DBA and Developer based use case¬†access to the wealth of instrumentation data implemented primarily within Performance Schema, but also with various INFORMATION_SCHEMA tables as well.…