Horton

Preparatory refactoring for parallel merge join support.

Robert Haas <rhaas@postgresql.org>

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Commit: a71f10189dc10a2fe422158a2c9409e0f77c6b9e
Author: Robert Haas <rhaas@postgresql.org>
Date: 2017-03-07T15:33:29Z
Releases: 10.0 
Preparatory refactoring for parallel merge join support.

Extract the logic used by hash_inner_and_outer into a separate
function, get_cheapest_parallel_safe_total_inner, so that it can
also be used to plan parallel merge joins.

Also, add a require_parallel_safe argument to the existing function
get_cheapest_path_for_pathkeys, because parallel merge join needs
to find the cheapest path for a given set of pathkeys that is
parallel-safe, not just the cheapest one overall.

Patch by me, reviewed by Dilip Kumar.

Discussion: http://postgr.es/m/CA+TgmoYOv+dFK0MWW6366dFj_xTnohQfoBDrHyB7d1oZhrgPjA@mail.gmail.com

Files

PathChange+/−
src/backend/optimizer/path/allpaths.c modified +6 −3
src/backend/optimizer/path/joinpath.c modified +6 −17
src/backend/optimizer/path/pathkeys.c modified +28 −1
src/include/optimizer/paths.h modified +3 −1

Discussion