Re: BUG #17245: Index corruption involving deduplicated entries - Mailing list pgsql-bugs

From Peter Geoghegan
Subject Re: BUG #17245: Index corruption involving deduplicated entries
Date
Msg-id CAH2-WzkhmPA-S3ODoCNkU0r3aAdiXOPnghfPEcD_LwdXgbCOFg@mail.gmail.com
Whole thread Raw
In response to Re: BUG #17245: Index corruption involving deduplicated entries  (Andres Freund <andres@anarazel.de>)
List pgsql-bugs
On Fri, Oct 29, 2021 at 1:59 PM Andres Freund <andres@anarazel.de> wrote:
> I'm considering writing a patch that
> 1) displays the number of tuples marked unused in HEAP2_PRUNE. This might only
>    be possible if no FPW was used
> 2) if a HEAP2_PRUNE or HEAP2_VACUUM isn't an FPW, display the offsets

> For 15 I think it might be worth to explicitly store the number of offets
> marked unused, rather than inferring that. It's hard to believe that the 16
> bit for that would be a relevant overhead, and having that more readily
> available seems like a significant improvement in debuggability.

I like that idea.

Attached is output from pg_filedump for heap page 540, with the page
header LSN reading 2/A019DC60. I have output, with and without the -i
option.

This doesn't have any of the real user data, which won't matter to you.

-- 
Peter Geoghegan

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