When optimizing queries and investigating performance issues, MySQL comes with built in support for profiling queries aka
SET profiling = 1;
. This is already awesome and simple to use, but why the PERFORMANCE_SCHEMA alternative?
Because profiling will be removed soon (already deprecated on MySQL 5.6 ad 5.7); the built-in profiling capability can only be enabled per session. This means that you cannot capture profiling information for queries running from other connections. If you are using Percona Server, the profiling option for log_slow_verbosity is a nice alternative, unfortunately, not everyone is using Percona Server.
Now, for a quick demo: I execute a …[Read more]