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Date: Tue, 07 May 2024 14:07:42 -0500
Message-Id: <D13NCMD86NAI.2RXKZAAJB3QW8@neon.tech>
Cc: "pgsql-hackers" <pgsql-hackers@postgresql.org>
Subject: Re: Use pgstat_kind_infos to read fixed shared stats structs
To: "Andres Freund" <andres@anarazel.de>
From: "Tristan Partin" <tristan@neon.tech>
References: <D12SQ7OYCD85.20BUVF3DWU5K7@neon.tech>
 <20240507182905.xfzlajkhvpi7frab@awork3.anarazel.de>
In-Reply-To: <20240507182905.xfzlajkhvpi7frab@awork3.anarazel.de>
Archived-At: 
 <https://www.postgresql.org/message-id/D13NCMD86NAI.2RXKZAAJB3QW8%40neon.tech>
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On Tue May 7, 2024 at 1:29 PM CDT, Andres Freund wrote:
> Hi,
>
> On 2024-05-06 14:07:53 -0500, Tristan Partin wrote:
> > Instead of needing to be explicit, we can just iterate the
> > pgstat_kind_infos array to find the memory locations to read into.
>
> > This was originally thought of by Andres in
> > 5891c7a8ed8f2d3d577e7eea34dacff12d7b6bbd.
> >=20
> > Not a fix, per se, but it does remove a comment. Perhaps the discussion=
 will
> > just lead to someone deleting the comment, and keeping the code as is.
> > Either way, a win :).
>
> I think it's a good idea. I'd really like to allow extensions to register=
 new
> types of stats eventually. Stuff like pg_stat_statements having its own,
> fairly ... mediocre, stats storage shouldn't be necessary.

Could be useful for Neon in the future too.

> Do we need to increase the stats version, I didn't check if the order we
> currently store things in and the numerical order of the stats IDs are th=
e
> same.

I checked the orders, and they looked the same.

1. Archiver
2. BgWriter
3. Checkpointer
4. IO
5. SLRU
6. WAL

--=20
Tristan Partin
Neon (https://neon.tech)