0002-Refactor-make_join_rel.patch

From 80861ce9a56d639833f015392bb6d4035a9deda2 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Fri, 3 Feb 2017 15:41:39 +0530
Subject: [PATCH 02/11] Refactor make_join_rel().

The code in make_join_rel() to add paths to join relation for a given pair of
joining relations can be re-used to add paths to a child join relation, which
do not need the other functionality offered by make_join_rel(). Separate this
code into populate_joinrel_with_paths(). This patch does just refactors
make_join_rel() to pave the way for partition-wise join.
---
 src/backend/optimizer/path/joinrels.c |   28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c
index 6f3c20b..936ee0c 100644
--- a/src/backend/optimizer/path/joinrels.c
+++ b/src/backend/optimizer/path/joinrels.c
@@ -32,6 +32,9 @@ static bool is_dummy_rel(RelOptInfo *rel);
 static void mark_dummy_rel(RelOptInfo *rel);
 static bool restriction_is_constant_false(List *restrictlist,
 							  bool only_pushed_down);
+static void populate_joinrel_with_paths(PlannerInfo *root, RelOptInfo *rel1,
+							RelOptInfo *rel2, RelOptInfo *joinrel,
+							SpecialJoinInfo *sjinfo, List *restrictlist);
 
 
 /*
@@ -724,6 +727,27 @@ make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
 		return joinrel;
 	}
 
+	/* Add paths to the join relation. */
+	populate_joinrel_with_paths(root, rel1, rel2, joinrel, sjinfo,
+								restrictlist);
+
+	bms_free(joinrelids);
+
+	return joinrel;
+}
+
+/*
+ * populate_joinrel_with_paths
+ *	  Add paths to the given joinrel for given pair of joining relations. The
+ *	  SpecialJoinInfo provides details about the join and the restrictlist
+ *	  contains the join clauses and the other clauses applicable for given pair
+ *	  of the joining relations.
+ */
+static void
+populate_joinrel_with_paths(PlannerInfo *root, RelOptInfo *rel1,
+							RelOptInfo *rel2, RelOptInfo *joinrel,
+							SpecialJoinInfo *sjinfo, List *restrictlist)
+{
 	/*
 	 * Consider paths using each rel as both outer and inner.  Depending on
 	 * the join type, a provably empty outer or inner rel might mean the join
@@ -868,10 +892,6 @@ make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
 			elog(ERROR, "unrecognized join type: %d", (int) sjinfo->jointype);
 			break;
 	}
-
-	bms_free(joinrelids);
-
-	return joinrel;
 }
 
 
-- 
1.7.9.5