Tom Lane <tgl@sss.pgh.pa.us> writes:
> Gregory Stark <stark@enterprisedb.com> writes:
>> So it occurs to me that freezing xmin won't actually do what we want for
>> indexcheckxmin. Namely it'll make the index *never* be used.
>
> How do you figure that? FrozenXID is certainly in the past from any
> vantage point.
Uhm, I'm not sure what I was thinking.
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.
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?
-- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's On-Demand Production
Tuning
