Tom Lane wrote: > --- 74,80 ---- > * That might actually be OK for the index scans, though. The newly inserted > * tuple wouldn't have an index pointer yet, so all tuples reachable from an > * index would still be visible to all other backends, and deletions > wouldn't > ! * be visible to other backends yet. (But HOT breaks that argument, no?)
The same argument holds for HOT. The new tuple has no index pointer, so it's not directly reachable from the index. Moreover, the value in the index is correct for both tuple versions, because a HOT update doesn't change index keys. In fact, if we only maintained the visibility map to enable index-only scans, a HOT update wouldn't need to clear the bit in the visibility map at all. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
