Re: Behaviour when autovacuum is canceled

On 2018-Sep-13, Martín Fernández wrote:

> By performing this changes we are going to start relying more heavily
> on the autovacuum work and the concern of "lost work" caused by
> autovacuum canceling itself when locking contention happen showed up.
> I'm guessing that we might be over thinking this and the canceling is
> not going to happen as frequently as we think it will.

Any DDL run on a table will cancel an autovacuum over that table (except
for-wraparound autovacuums). If these are rare, you don't need to worry
about that too much. If they are frequent enough that autovacuum will
be cancelled regularly in one table, you'll be sad.

If you're running vacuum by hand, you'd probably see your DDL blocking
behind VACUUM, which would be very noticeable. I think if you don't
have trouble today without having tuned the system carefully to avoid
such trouble, you're not likely to have trouble with autovacuum either.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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