Re: index prefetching - Mailing list pgsql-hackers

From Andres Freund
Subject Re: index prefetching
Date
Msg-id 76E3F022-3F9E-42C4-8AFF-1786CB2855FA@anarazel.de
Whole thread Raw
In response to Re: index prefetching  (Peter Geoghegan <pg@bowt.ie>)
Responses Re: index prefetching
List pgsql-hackers
Hi,

On August 15, 2025 3:25:50 PM EDT, Peter Geoghegan <pg@bowt.ie> wrote:
>On Thu, Aug 14, 2025 at 10:12 PM Peter Geoghegan <pg@bowt.ie> wrote:
>> As far as I know, we only have the following unambiguous performance
>> regressions (that clearly need to be fixed):
>>
>> 1. This issue.
>>
>> 2. There's about a 3% loss of throughput on pgbench SELECT.
>
>I did a quick pgbench SELECT benchmark again with Andres' patch, just
>to see if that has been impacted. Now the regression there is much
>larger; it goes from a ~3% regression to a ~14% regression.
>
>I'm not worried about it. Andres' "not waiting for already-in-progress
>IO" patch was clearly just a prototype. Just thought it was worth
>noting here.

Are you confident in that? Because the patch should be extremely cheap in that case. What precisely were you testing?

Andres
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.



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