Re: BUG #17485: Records missing from Primary Key index when doing REINDEX INDEX CONCURRENTLY

On 2022-May-23, Michael Paquier wrote:

> It took me some time to write a script to bisect that, but I have been
> able to establish a correlation with d9d0762 that causes VACUUM to
> ignore transactions doing some concurrent reindex operations. I would
> not be surprised to see that this is also related to some of the
> reports we have seen lately with reindex operations. There was one
> with logical replication and missing records from a primary key, I
> recall.
>
> For the stable branches of 14 and 15, I would tend to play it safe and
> revert d9d0762. I have to admit that f9900df and c98763b stress me a
> bit, and that we have not have anticipated all the ramifications of
> this set of changes. Thoughts?

Wow, thanks for researching that over the weekend.

I think if this is a big enough deal (and I think it may be) then IMO we
should revert as you suggest, make an out-of-schedule release, and then
I can take some time to investigate in more depth and see if the feature
can be salvaged.

OTOH if we think an out-of-schedule release is not warranted, then
reverting right now is not useful; we can make a decision about that
closer to the next minor release, once we've had time to see if the bug
can be fixed in some other way that doesn't break the whole feature.

Opinions?

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Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
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