From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ron Johnson <ronljohnsonjr@gmail.com>
cc: pgsql-general <pgsql-general@postgresql.org>
Subject: Re: Loading the latest N rows into the cache seems way too fast.
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Comments: In-reply-to Ron Johnson <ronljohnsonjr@gmail.com>
	message dated "Mon, 17 Feb 2025 15:32:47 -0500"
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Date: Mon, 17 Feb 2025 16:36:37 -0500
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Ron Johnson <ronljohnsonjr@gmail.com> writes:
> The bigint "id" column in "mytbl" is populated from a sequence, and so is
> monotonically increasing: the newest records will have the biggest id
> values.
> The table also has a bytea column that averages about 100KB.

> Loading 200K rows is more than 200MB.  I expected this "prewarm" statement
> to take much longer than 1/2 second.  Am I still in the dark ages of
> computer speed, or is this statement not doing what I hope it's doing?

It's not pulling in the TOAST storage where the bytea column lives.
(pg_prewarm wouldn't have either, without special pushups.)

			regards, tom lane