RE: [PROPOSAL] Termination of Background Workers for ALTER/DROP DATABASE

Hi

Thank you for your comments and suggestions on the previous version patches!
I believe this feature become much better.

I've created a v13 patch incorporating Peter-san's suggestions.

> One issue with the test as written, as of run_db_command(), is that we
> make sure that a worker is stopped by scanning the output of the logs.
> This approach may detect incorrect patterns, unfortunately. For
> example, if the termination logic has a bug it may be possible that
> the worker found as terminated is the first one created by the test,
> which we expect to always run. While the log is mandatory to have, I
> have a suggestion to make that even better: let's keep track in
> run_db_command() of the PIDs of the worker processes we expect to
> exist after running each database command, then make sure that the
> list of PIDs match with what we expect. This is a bit simpler in the
> case of this test as we only expect one matching PID.

I've also reviewed the test set code comparing PIDs. I think this is acceptable.

Best Regards,
Aya Iwata