Horton

Re: Doc fix of aggressive vacuum threshold for multixact members storage

Alex Friedman <alexf01@gmail.com>

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From: Alex Friedman <alexf01@gmail.com>
To: Sami Imseih <samimseih@gmail.com>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2025-02-04T16:48:09Z
Lists: pgsql-hackers

Attachments

> A few paragraphs up the docs, there is this mention:
> 
> ". There is a separate storage area which holds the list of members
> in each multixact, which also uses a 32-bit counter and which must
> also be managed."
> 
> Maybe we can add more to this paragraph, such as:
> 
> "also be managed. This member can grow to 20GB"
> 
> And then in the proposed correction:
> 
> "
> Also, if the storage occupied by multixacts members area exceeds 10GB
> (50% of the maximum the members area can grow), aggressive vacuum
> scans will occur more often for all tables
> "
> 
> What do you think?
> 

Looks good to me, attached a v2 patch with small adjustments.


Thanks,

Alex

Commits

  1. Doc: correct aggressive vacuum threshold for multixact members storage

  2. docs: clarify new aggressive vacuum mode for multi-xacts

  3. Increase threshold for multixact member emergency autovac to 50%.