Re: [HACKERS] [PROPOSAL] Use SnapshotAny in get_actual_variable_range

Andres Freund <andres@anarazel.de> writes:
> On 2017-04-27 17:22:25 -0400, Tom Lane wrote:
>> How so?  Shouldn't the indexscan go back and mark such tuples dead in
>> the index, such that they'd be visited this way only once?  If that's
>> not happening, maybe we should try to fix it.

> One way that never happens is if you end up choosing bitmap index scans
> all the time...

What I'm thinking of is the regular indexscan that's done internally
by get_actual_variable_range, not whatever ends up getting chosen as
the plan for the user query.  I had supposed that that would kill
dead index entries as it went, but maybe that's not happening for
some reason.
        regards, tom lane