Sessions table not beeing cleared

Hello. I have CI 3, and maybe it's been replaced by now with newer systems(?)

It's working as far as I know.

I looked in the ci_sessions table.

The oldest row has a timestamp corresponding to 8/3/2019, 10:56:56 PM.

I saw in the forum there was a thread about this, but I saw only something about garbage-collecting, which I didn't find in the code-files.

Is this table supposed to be cleared automatically?

I have another question too; can I count how many persons are logged in by using this ci_sessions table.

Greetings Valema