Re: admin control over cancelling autovacuum when blocked by a lock

Simon Riggs <simon(at)2ndquadrant(dot)com> writes:
> On Mon, 29 Apr 2019 at 22:02, John Lumby <johnlumby(at)hotmail(dot)com> wrote:
>> If a regular backend worker becomes blocked waiting for a lock held by an
>> autovacuum worker,
>> then , depending on some decision made by deadlock detector,
>> the autovacuum worker may be signalled to terminate
>> Is there any configuration parameter which controls this?
>> including deferring or even completely eliminating this cancelling?

> Why would you want this?
> If the autovacuum is cancelled, it will re-execute again in the near
> future, once your interrupting SQL has released locks.

I think the OP is looking for the opposite, ie prevent autovacuum from
being kicked off the lock. It already is resistant to that if we're
doing an anti-wraparound vacuum, so maybe the simplest answer is to
tighten up autovacuum_freeze_max_age. (Whether that's a good idea
is a different question.) Or you could just launch a manual vacuum.

regards, tom lane