Re: [PERFORM] COUNT(*) again (was Re: Index/Function organized

Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Tom Lane wrote:
> >> I think that's not happening, conditionally or otherwise.  The atomicity
> >> problems alone are sufficient reason why not, even before you look at
> >> the performance issues.
>
> > What are the atomicity problems of adding a create/expire xid to the
> > index tuples?
>
> You can't update a tuple's status in just one place ... you have to
> update the copies in the indexes too.

But we don't update the tuple status for a commit, we just mark the xid
as committed.  We do have lazy status bits that prevent later lookups in
pg_clog, but we have those in the index already also.

What am I missing?

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