diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2023-04-05 16:59:00 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2023-04-05 16:59:09 -0400 |
| commit | 16dc2703c5413534d4989e08253e8f4fcb0e2aab (patch) | |
| tree | c25f739d183d93510418b734ebd36fc3e2e9fde9 /src/include/nodes/pathnodes.h | |
| parent | dad50f677c42de207168a3f08982ba23c9fc6720 (diff) | |
Support "Right Anti Join" plan shapes.
Merge and hash joins can support antijoin with the non-nullable input
on the right, using very simple combinations of their existing logic
for right join and anti join. This gives the planner more freedom
about how to order the join. It's particularly useful for hash join,
since we may now have the option to hash the smaller table instead
of the larger.
Richard Guo, reviewed by Ronan Dunklau and myself
Discussion: https://postgr.es/m/CAMbWs48xh9hMzXzSy3VaPzGAz+fkxXXTUbCLohX1_L8THFRm2Q@mail.gmail.com
Diffstat (limited to 'src/include/nodes/pathnodes.h')
| -rw-r--r-- | src/include/nodes/pathnodes.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h index d61a62da196..cf28416da84 100644 --- a/src/include/nodes/pathnodes.h +++ b/src/include/nodes/pathnodes.h @@ -2766,8 +2766,9 @@ typedef struct PlaceHolderVar * min_lefthand and min_righthand for higher joins.) * * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching - * the inputs to make it a LEFT JOIN. So the allowed values of jointype - * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI. + * the inputs to make it a LEFT JOIN. It's never JOIN_RIGHT_ANTI either. + * So the allowed values of jointype in a join_info_list member are only + * LEFT, FULL, SEMI, or ANTI. * * ojrelid is the RT index of the join RTE representing this outer join, * if there is one. It is zero when jointype is INNER or SEMI, and can be |