Re: Bitmapscan changes - Mailing list pgsql-patches

From Tom Lane
Subject Re: Bitmapscan changes
Date
Msg-id 15358.1173710210@sss.pgh.pa.us
Whole thread Raw
In response to Bitmapscan changes  (Heikki Linnakangas <heikki@enterprisedb.com>)
Responses Re: Bitmapscan changes  (Heikki Linnakangas <heikki@enterprisedb.com>)
List pgsql-patches
Heikki Linnakangas <heikki@enterprisedb.com> writes:
> The patch also adds support for candidate matches. An index scan can
> indicate that the tuples it's returning are candidates, and the executor
> will recheck the original scan quals of any candidate matches when the
> tuple is fetched from heap.

This will not work, unless we change the planner --- the original quals
aren't necessarily there in some corner cases (partial indexes, if
memory serves).

> The motivation for adding the support for candidate matches is that GIT
> / clustered indexes need it.

You need more than a vague reference to an unapplied patch to convince
me we ought to do this.

            regards, tom lane

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