From: Tomas Vondra <tomas@2ndquadrant.com>
Date: Sun, 22 Jan 2017 18:06:42 +0000 (+0100)
Subject: remove the 'distribution' field from SubqueryScanPath
X-Git-Tag: XL_10_R1BETA1~409
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=c6f1dc34e84341b7b5ddaa082f162755edec727c;p=postgres-xl.git

remove the 'distribution' field from SubqueryScanPath

Considering there's a distribution field in every Path (which
the SubqueryScanPath includes), this seems unnecessary and quite
confusing, because sometimes we work with (Path*) directly, and
sometimes through the 'path' field. It took me quite a bit of
time to realize that when create_subqueryscan_path does

    pathnode->distribution = X

it's not the same as doing

    pathnode->path.distribution = X

Note: It's possible that we in fact need the separate field for
somehow transformed distribution?
---

diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index cbec3cd34f..ae8faf3a2a 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -3066,7 +3066,7 @@ create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
 	SubqueryScanPath *pathnode = makeNode(SubqueryScanPath);
 
 #ifdef XCP
-	pathnode->distribution = distribution;
+	pathnode->path.distribution = distribution;
 #endif
 	pathnode->path.pathtype = T_SubqueryScan;
 	pathnode->path.parent = rel;
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 77554872a6..c0bd1a7bc8 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -1077,7 +1077,6 @@ typedef struct SubqueryScanPath
 {
 	Path		path;
 	Path	   *subpath;		/* path representing subquery execution */
-	Distribution *distribution; /* result distribution */
 } SubqueryScanPath;
 
 /*