The Performance Schema and sys
schema are great for
investigating what is going on in MySQL including investigating
performance issues. In my work in MySQL Support, I have a several
times heard questions whether a peak in the InnoDB Data File
I/O – Latency graph in MySQL Enterprise Monitor (MEM) or
some values from the corresponding tables and view in the
Performance Schema and sys
schema are cause for
concern. This blog will discuss what these observations means and
how to use them.
The Tables and Views Involved
…
[Read more]