On 16.01.2018 10:49, Jeff Davis wrote:
> My proposed fix is to make an internal opfamily identical to the
> external one, such that it's not recognized as part of the same EC,
> and the planner won't try to eliminate it. It loses out on potential
> optimizations, but those are mostly theoretical since the btree
> opclass ordering for ranges is not very interesting to a user.
I think I figured out what to do with missing sort directions. We can
change select_outer_pathkeys_for_merge() to generate the pathkeys we
need. Also, find_mergeclauses_for_outer_pathkeys() has to be changed
too, so that it knows which pathkeys are compatible to which range join
clauses.
About the patch, do I understand it right that you are working on the
next version now?
--
Alexander Kuzmenkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company