Re: Potential problem with HOT and indexes?

Gregory Stark <stark@enterprisedb.com> writes:
> Another thought now though. What if someone updates the pg_index entry --
> since we never reset indcheckxmin then the new tuple will have a new xmin and
> will suddenly become invisible again for no reason.

Hmm ... if updates to pg_index entries were common then I could get
worried about that, but they really aren't.

> Couldn't this happen if you set a table WITHOUT CLUSTER for example? Or if
> --as possibly happened in the user's case-- you reindex the table and don't
> find any HOT update chains but the old pg_index entry had indcheckxmin set
> already?

This is all useless guesswork until we find out whether he was using
REINDEX or CREATE INDEX CONCURRENTLY.
        regards, tom lane