Re: First draft of PG 17 release notes

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(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

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