Re: pgstat vs aset

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Andres Freund <andres@anarazel.de>

Cc: pgsql-hackers@postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>, Alexander Lakhin <exclusion@gmail.com>, Sami Imseih <samimseih@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Treat <rob@xzilla.net>, satyanarlapuram@gmail.com, tndrwang@gmail.com

Date: 2026-04-09T14:50:49Z

Lists: pgsql-hackers

On Wed, Apr 08, 2026 at 07:04:58PM -0400, Andres Freund wrote:
> In [1] I looked at pgstat memory usage after sort of a complaint by Nathan.
> The conversion of "PgStat Shared Ref" to slab seems like an improvement we
> obviously should make [2].
>
> [...]
> 
> But I think for this use case we actually have a more fitting memory context
> type for this workload, i.e. GenerationContext.  With that the size after the
> same vacuum is

Nice.

> [2] It's a big enough saving that I'm kinda wondering about whether we should
> try to sneak it into 19.

I don't know whether it's appropriate to try to sneak this into v19 at this
point, but it at least seems like a "moment v20 opens for development"
thing.  Should we double check there's no meaningful performance
differences?  Otherwise, this seems like an easy win.

-- 
nathan