Date: Sat, 25 May 2024 23:49:03 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: First draft of PG 17 release notes
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On Thu, May 23, 2024 at 01:22:51PM +0200, Álvaro Herrera wrote:
> Hello,
> 
> Regarding this item
> 
> : Allow the SLRU cache sizes to be configured (Andrey Borodin, Dilip Kumar)
> : 
> : The new server variables are commit_timestamp_buffers,
> : multixact_member_buffers, multixact_offset_buffers, notify_buffers,
> : serializable_buffers, subtransaction_buffers, and transaction_buffers.
> 
> I hereby request to be listed as third author of this feature.
> 
> Also, I'd like to suggest to make it more verbose, as details might be
> useful to users.  Mention that scalability is improved, because
> previously we've suggested to recompile with larger #defines, but to be
> cautious because values too high degrade performance.  Also mention the
> point that some of these grow with shared_buffers is user-visible enough
> that it warrants an explicit mention.  How about like this:
> 
> : Allow the SLRU cache sizes to be configured and improve performance of
> : larger caches
> : (Andrey Borodin, Dilip Kumar, Álvaro Herrera)
> : 
> : The new server variables are commit_timestamp_buffers,
> : multixact_member_buffers, multixact_offset_buffers, notify_buffers,
> : serializable_buffers, subtransaction_buffers, and transaction_buffers.
> : commit_timestamp_buffers, transaction_buffers and
> : subtransaction_buffers scale up automatically with shared_buffers.

Yes, I like that, patch applied.

> These three items
> 
> : Allow pg_stat_reset_shared() to reset all shared statistics (Atsushi Torikoshi)
> : 
> : This is done by passing NULL.
> : 
> : Allow pg_stat_reset_shared('slru') to clear SLRU statistics (Atsushi Torikoshi)
> : 
> : Now pg_stat_reset_shared(NULL) also resets SLRU statistics.
> : 
> : Allow pg_stat_reset_slru() to reset all SLRU statistics (Bharath Rupireddy)
> : 
> : The command pg_stat_reset_slru(NULL) already did this.
> 
> seem a bit repetitive.  (I think the first one is also wrong, because it
> says you have to pass NULL, but in reality you can also not give an
> argument and it works.)  Can we make them a single item?  Maybe
> something like
> 
> : Improve reset routines for shared statistics (Atsushi Torikoshi, Bharath Rupireddy)
> :
> : Resetting all shared statistics can now be done with
> : pg_stat_reset_shared() or pg_stat_reset_shared(NULL), while SLRU
> : statistics can now be reset with pg_stat_reset_shared('slru'),
> : pg_stat_reset_slru() and pg_stat_reset_slru(NULL).

Andres already suggested improvement for this, and I posted the applied
patch.  Can you see if that is good or can be improved?  Thanks.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.