Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin
Date
Msg-id CAH2-WznnDZgZAOUins9ye8_=Y=892N2mvjs9bUB8s37gXnOKQQ@mail.gmail.com
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In response to Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin  (Melanie Plageman <melanieplageman@gmail.com>)
Responses Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin
List pgsql-hackers
On Wed, Jul 17, 2024 at 12:07 PM Melanie Plageman
<melanieplageman@gmail.com> wrote:
> We didn't end up doing two index vacuum passes. Because it doesn't
> repro locally for me, I can only assume that the conditions for
> forcing two index vacuuming passes in master just weren't met in this
> case. I'm unsurprised, as it is much harder since 17 to force two
> passes of index vacuuming. It seems like this might be as unstable as
> I feared. I could add more dead data. Or, I could just commit the test
> to the back branches before 17. What do you think?

How much margin of error do you have, in terms of total number of
dead_items? That is, have you whittled it down to the minimum possible
threshold for 2 passes?

Some logging with VACUUM VERBOSE (run on the ci instance) might be illuminating.


--
Peter Geoghegan



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