Re: BUG #15111: c between x and x gives bad planning

=?utf-8?q?PG_Bug_reporting_form?= <noreply@postgresql.org> writes:
> Scenario: A table with columns a,b,c. Btree index on a,c. Gist index on b,c.
> A query with a clause a = y and c between x and x uses the gist index b,c
> instead of a,c, with very worst execution time than when c between x and z,
> even with small deltas (x,z), when the btree (a,c) is used.

This has been improved for v11, cf

https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=7d08ce286

That won't be back-patched, though --- even if we were inclined to take
the risk of doing so, the catalog changes make it impractical.

            regards, tom lane