Re: Parallel heap vacuum - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Parallel heap vacuum
Date
Msg-id xymq6plhuujm6rpb3hyqpwqkqo3q6kdx2a6nnei6sgpbzzj7lb@ejwunmymqgxb
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In response to Re: Parallel heap vacuum  (Tomas Vondra <tomas@vondra.me>)
Responses Re: Parallel heap vacuum
Re: Parallel heap vacuum
List pgsql-hackers
Hi,

On 2025-09-17 13:25:11 +0200, Tomas Vondra wrote:
> I believe the reason why parallelism is disabled in autovacuum is that
> we want autovacuum to be a background process, with minimal disruption
> to user workload. It probably wouldn't be that hard to allow autovacuum
> to do parallel stuff, but it feels similar to adding autovacuum workers.
> That's rarely the solution, without increasing the cost limit.

I continue to find this argument extremely unconvincing. It's very common for
autovacuum to be continuously be busy with the one large table that has a
bunch of indexes. Vacuuming that one table is what prevents the freeze horizon
to move forward / prevents getting out of anti-wraparound territory in time.

Greetings,

Andres Freund



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