Michael Paquier <michael(at)paquier(dot)xyz> writes:
> How long can the backend remain unresponsive? I don't think that
> anybody would object to the addition of some CHECK_FOR_INTERRUPTS() in
> areas where it would be efficient to make the shutdown quicker, but
> we need to think carefully about the places where we'd want to add
> these.
CHECK_FOR_INTERRUPTS is really quite cheap, just a test-and-branch.
I wouldn't put it in a *very* tight loop, but one test per row
processed while gathering stats is unlikely to be a problem.
regards, tom lane