v21-0001-Reduce-code-duplication-in-set_append_rel_size.patch

From 8f792a8492d5579c238cea8ba24bbebe6ace4d46 Mon Sep 17 00:00:00 2001
From: amit <amitlangote09@gmail.com>
Date: Fri, 8 Feb 2019 15:06:25 +0900
Subject: [PATCH v21 1/6] Reduce code-duplication in set_append_rel_size

The code to mark a child rel dummy is repeated for 3 cases:

 * child is pruned,
 * contradictory quals found in apply_child_quals,
 * child excluded due to constraints.

This combines the three cases in one if statement.
---
 src/backend/optimizer/path/allpaths.c | 39 +++++++++++------------------------
 1 file changed, 12 insertions(+), 27 deletions(-)

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 55b871c02c..130efd6023 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -1015,6 +1015,7 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
 		RelOptInfo *childrel;
 		ListCell   *parentvars;
 		ListCell   *childvars;
+		bool		childpruned;
 
 		/* append_rel_list contains all append rels; ignore others */
 		if (appinfo->parent_relid != parentRTindex)
@@ -1030,36 +1031,20 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
 		childrel = find_base_rel(root, childRTindex);
 		Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
 
-		if (did_pruning && !bms_is_member(appinfo->child_relid, live_children))
-		{
-			/* This partition was pruned; skip it. */
-			set_dummy_rel_pathlist(childrel);
-			continue;
-		}
-
+		childpruned = (did_pruning &&
+					   !bms_is_member(appinfo->child_relid, live_children));
 		/*
-		 * We have to copy the parent's targetlist and quals to the child,
-		 * with appropriate substitution of variables.  If any constant false
-		 * or NULL clauses turn up, we can disregard the child right away.
-		 * If not, we can apply constraint exclusion with just the
-		 * baserestrictinfo quals.
+		 * Unless the child is pruned, we have to copy the parent's targetlist
+		 * and quals to the child, with appropriate substitution of variables.
+		 * If any constant false or NULL clauses turn up, we can disregard the
+		 * child right away.  If not, we can apply constraint exclusion with
+		 * just the baserestrictinfo quals.
 		 */
-		if (!apply_child_basequals(root, rel, childrel, childRTE, appinfo))
+		if (childpruned ||
+			!apply_child_basequals(root, rel, childrel, childRTE, appinfo) ||
+			relation_excluded_by_constraints(root, childrel, childRTE))
 		{
-			/*
-			 * Some restriction clause reduced to constant FALSE or NULL after
-			 * substitution, so this child need not be scanned.
-			 */
-			set_dummy_rel_pathlist(childrel);
-			continue;
-		}
-
-		if (relation_excluded_by_constraints(root, childrel, childRTE))
-		{
-			/*
-			 * This child need not be scanned, so we can omit it from the
-			 * appendrel.
-			 */
+			/* This partition needn't be scanned; skip it. */
 			set_dummy_rel_pathlist(childrel);
 			continue;
 		}
-- 
2.11.0