Performance schema performance tuning One of the most important
question users ask before deciding to use the performance schema
is: what is the overhead ? The underlying concern of course is to
make sure deploying the performance schema does not negatively
impact production ("First, do no harm").
The question is simple, and yet the answer is not so simple, as
it depends on so many things.
As seen in some benchmarks done already, the overhead when using
the performance schema can vary a lot, and in some cases really
causes degradations.
A lot of time has been spent investigating the root causes (note
the plural form) for the performance schema overhead in general,
so I think it is a good time to share current findings.
Server workload Analysing performances, and testing the effects
of different code or configuration changes, can hardly be done in
a vacuum. That's where benchmarks come in.
The problem with …