Message-ID: <79bc2b67-b0c1-4945-a5df-1b4f71d32a48@gmail.com>
Date: Fri, 17 Apr 2026 16:40:09 +0200
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Subject: Re: First draft of PG 19 release notes
To: Bruce Momjian <bruce@momjian.us>
Cc: PostgreSQL-development <pgsql-hackers@lists.postgresql.org>
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From: David Geier <geidav.pg@gmail.com>
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On 16.04.2026 18:14, Bruce Momjian wrote:
>> How about also including the improvements we did for reducing GIN index
>> build times, see [1]? Not all patches have been committed yet but the
>> ones that got committed already make a meaningful difference.
>>
>> [1]
>> https://www.postgresql.org/message-id/flat/5d366878-2007-4d31-861e-19294b7a583b%40gmail.com
> 
> This is an interesting case.  First, I looked at the commit logs and
> didn't see anything talking about improving the speed of GIN index
> builds.  So then I looked at the first email in the thread and saw 3x
> improvement for pg_trgm, so I looked in the commit logs for pg_trgm and
> didn't see any speedup mentioned.
> 
> I then looked at the posted patches and this might be a case where there
> are a number of targeted improvements that didn't specify the larger
> goal, so there is no goal mentioned in the commit logs.  This is an edge
> case that is hard to get into the release notes.
> 
> Now that you have told me about it, here is my normal criteria for
> adding performance items to the release notes:
> 
> 	Performance improvements are mentioned in the release notes if
> 	they are user-visible (e.g., new syntax) or significant enough
> 	to enable new workloads.
> 
> So, it seems there is no user-visible change, except it is faster.  Does
> it enable new workloads?  A 3x speedup probably does.  Should this be a
> pg_trgm item, with a description mentioning GIN in general, or should it
> be a GIN item, perhaps mentioning pg_trgm?  Do you have any suggested
> text and list of commits?

Not all patches from the initial mail have been committed yet. Hence,
currently the speed up is less. However, once they got all committed
they would indeed open up new "use cases". For example, I know users
that don't add GIN indexes to very large tables because creating them
takes too long.

--
David Geier