public inbox for [email protected]  
help / color / mirror / Atom feed
From: Tom Lane <[email protected]>
To: Ron Johnson <[email protected]>
Cc: pgsql-general <[email protected]>
Subject: Re: Loading the latest N rows into the cache seems way too fast.
Date: Mon, 17 Feb 2025 16:36:37 -0500
Message-ID: <[email protected]> (raw)
In-Reply-To: <CANzqJaBTPgTJ_M3dGiOa5H-FvAo71oCCa1QHejbzK+joKdrSyw@mail.gmail.com>
References: <CANzqJaBTPgTJ_M3dGiOa5H-FvAo71oCCa1QHejbzK+joKdrSyw@mail.gmail.com>

Ron Johnson <[email protected]> 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






view thread (6+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected]
  Subject: Re: Loading the latest N rows into the cache seems way too fast.
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox