Re: allow changing autovacuum_max_workers without restarting - Mailing list pgsql-hackers

From Imseih (AWS), Sami
Subject Re: allow changing autovacuum_max_workers without restarting
Date
Msg-id 96B4FC7B-A919-4F93-80A3-BA3EA4F8479A@amazon.com
Whole thread Raw
In response to Re: allow changing autovacuum_max_workers without restarting  (Nathan Bossart <nathandbossart@gmail.com>)
Responses Re: allow changing autovacuum_max_workers without restarting
Re: allow changing autovacuum_max_workers without restarting
List pgsql-hackers
> Another option could be to just remove the restart-only GUC and hard-code
> the upper limit of autovacuum_max_workers to 64 or 128 or something. While
> that would simplify matters, I suspect it would be hard to choose an
> appropriate limit that won't quickly become outdated.

Hardcoded values are usually hard to deal with because they are hidden either
In code or in docs.

> When I thought about this, I considered proposing to add a new GUC for
> "autovacuum_policy_workers".

> autovacuum_max_workers would be the same as before, requiring a restart
> to change.  The policy GUC would be the soft limit, changable at runtime

I think autovacuum_max_workers should still be the GUC that controls
the number of concurrent autovacuums. This parameter is already well 
established and changing the meaning now will be confusing. 

I suspect most users will be glad it's now dynamic, but will probably 
be annoyed if it's no longer doing what it's supposed to.

Regards,

Sami 


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