Re: Loading the latest N rows into the cache seems way too fast.

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Ron Johnson <ronljohnsonjr(at)gmail(dot)com>
Cc: pgsql-general <pgsql-general(at)postgresql(dot)org>
Subject: Re: Loading the latest N rows into the cache seems way too fast.
Date: 2025-02-17 21:36:37
Message-ID: 931647.1739828197@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Ron Johnson <ronljohnsonjr(at)gmail(dot)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

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Ron Johnson 2025-02-17 21:40:56 Re: Loading the latest N rows into the cache seems way too fast.
Previous Message Robert Haas 2025-02-17 21:34:45 Re: Clarification on Role Access Rights to Table Indexes