Is there a way to query of all the current connections and to see if they are using compression?
I know you can query your current connection using:
SHOW SESSION STATUS LIKE "Compression";
This will return a table with the value column saying ON or OFF.
However, this is not what I want. I would rather have something like SHOW PROCESSLIST that has a column indicating whether or not someone's connection has compression enabled.
Since compression is strictly in the scope of a session, it is currently impossible to query data from another session in MySQL directly.
Is there a way to see the SESSION variables of other active, connected users, from a superuser connection ?
No, there is no way.