Re: Loading the latest N rows into the cache seems way too fast. - Mailing list pgsql-general

From Ron Johnson
Subject Re: Loading the latest N rows into the cache seems way too fast.
Date
Msg-id CANzqJaC=6pUTsveOdL=FS1vz_FGjMbZKuzJ27JxsPfNbYN2fUA@mail.gmail.com
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In response to Re: Loading the latest N rows into the cache seems way too fast.  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
On Mon, Feb 17, 2025 at 4:51 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Ron Johnson <ronljohnsonjr@gmail.com> writes:
> On Mon, Feb 17, 2025 at 4:36 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> It's not pulling in the TOAST storage where the bytea column lives.
>> (pg_prewarm wouldn't have either, without special pushups.)

> Puzzling, since I ran "PERFORM *".  What if I explicitly mentioned the
> bytea column's name?

You'd have to do something that actually used the column's value,
perhaps "md5(byteacol)" or such.  (The obvious candidate would be
length(), but I think that is optimized to not fetch or decompress
the whole value.)

That's definitely taking a LOT longer...

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