Date: Tue, 9 Jul 2024 18:23:50 +0200
From: Christoph Moench-Tegeder <cmt@burggraben.net>
To: "Shenavai, Manuel" <manuel.shenavai@sap.com>
Cc: pgsql-general <pgsql-general@postgresql.org>
Subject: Re: autovacuum_vacuum_cost_delay
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## Shenavai, Manuel (manuel.shenavai@sap.com):

> Looking at autovacuum_vacuum_cost_delay:
> https://www.postgresql.org/docs/current/runtime-config-autovacuum.html#GUC-AUTOVACUUM-VACUUM-COST-DELAY
> 
> Can someone help to understand what a high or low value of this setting really means? Would it be OK to set this to 0? If not, why not?

The autovacuum settings link to the docs of the regular vacuum settings:
https://www.postgresql.org/docs/current/runtime-config-resource.html#RUNTIME-CONFIG-RESOURCE-VACUUM-COST
which explains the parameters at least as good as I could do here.
You can set autovacuum_vacuum_cost_delay to 0 - that would give you
"unlimited" autovacuum bandwidth (limited by whatever your system and
your other configuration can give you). That might create very
noticeable performance impact on the actual workload, which is most
often rather undesirable.
In short: it's possible to set that parameter to 0, but that could
well be a not-so-good idea.

Regards,
Christoph

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