v1-0001-Replace-lateral-references-to-removed-rels-in-subqueries.patch

From b70cb2f48defdf5e2bf66e08bbee122076d829d0 Mon Sep 17 00:00:00 2001
From: Richard Guo <guofenglinux@gmail.com>
Date: Wed, 21 Feb 2024 14:15:33 +0800
Subject: [PATCH v1] Replace lateral references to removed rels in subqueries

---
 src/backend/optimizer/plan/analyzejoins.c | 147 +++++++------
 src/test/regress/expected/join.out        | 256 +++++++++++-----------
 src/test/regress/sql/join.sql             | 196 +++++++++--------
 3 files changed, 311 insertions(+), 288 deletions(-)

diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c
index 072298f66c..e5e0df1374 100644
--- a/src/backend/optimizer/plan/analyzejoins.c
+++ b/src/backend/optimizer/plan/analyzejoins.c
@@ -34,15 +34,6 @@
 #include "optimizer/tlist.h"
 #include "utils/lsyscache.h"
 
-/*
- * The context for replace_varno_walker() containing source and target relids.
- */
-typedef struct
-{
-	int			from;
-	int			to;
-} ReplaceVarnoContext;
-
 /*
  * The struct containing self-join candidate.  Used to find duplicate reloids.
  */
@@ -75,13 +66,11 @@ static bool is_innerrel_unique_for(PlannerInfo *root,
 								   JoinType jointype,
 								   List *restrictlist,
 								   List **extra_clauses);
-static Bitmapset *replace_relid(Relids relids, int oldId, int newId);
 static void replace_varno(Node *node, int from, int to);
-static bool replace_varno_walker(Node *node, ReplaceVarnoContext *ctx);
+static Bitmapset *replace_relid(Relids relids, int oldId, int newId);
 static int	self_join_candidates_cmp(const void *a, const void *b);
 
 
-
 /*
  * remove_useless_joins
  *		Check for relations that don't actually need to be joined at all,
@@ -367,7 +356,8 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel,
 	ListCell   *l;
 
 	/*
-	 * Remove references to the rel from other baserels' attr_needed arrays.
+	 * Remove references to the rel from other baserels' attr_needed arrays and
+	 * lateral_vars lists.
 	 */
 	for (rti = 1; rti < root->simple_rel_array_size; rti++)
 	{
@@ -394,35 +384,8 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel,
 				replace_relid(otherrel->attr_needed[attroff], ojrelid, subst);
 		}
 
-		/* Update lateral references. */
-		if (root->hasLateralRTEs)
-		{
-			RangeTblEntry *rte = root->simple_rte_array[rti];
-			ReplaceVarnoContext ctx = {.from = relid,.to = subst};
-
-			if (rte->lateral)
-			{
-				replace_varno((Node *) otherrel->lateral_vars, relid, subst);
-
-				/*
-				 * Although we pass root->parse through cleanup procedure,
-				 * but parse->rtable and rte contains refs to different copies
-				 * of the subquery.
-				 */
-				if (otherrel->rtekind == RTE_SUBQUERY)
-					query_tree_walker(rte->subquery, replace_varno_walker, &ctx,
-									  QTW_EXAMINE_SORTGROUP);
-#ifdef USE_ASSERT_CHECKING
-				/* Just check possibly hidden non-replaced relids */
-				Assert(!bms_is_member(relid, pull_varnos(root, (Node *) rte->tablesample)));
-				Assert(!bms_is_member(relid, pull_varnos(root, (Node *) rte->functions)));
-				Assert(!bms_is_member(relid, pull_varnos(root, (Node *) rte->tablefunc)));
-				Assert(!bms_is_member(relid, pull_varnos(root, (Node *) rte->values_lists)));
-#endif
-			}
-		}
-
-
+		/* Update lateral_vars list. */
+		replace_varno((Node *) otherrel->lateral_vars, relid, subst);
 	}
 
 	/*
@@ -1462,35 +1425,32 @@ is_innerrel_unique_for(PlannerInfo *root,
 }
 
 /*
- * Replace each occurrence of removing relid with the keeping one
+ * replace_varno - find any Vars, PlaceHolderVar and Relids in the given tree
+ * that reference the removing relid, and change them to reference the
+ * replacement relid.
+ *
+ * NOTE: although this has the form of a walker, we cheat and modify the
+ * nodes in-place.
  */
-static void
-replace_varno(Node *node, int from, int to)
-{
-	ReplaceVarnoContext ctx;
-
-	if (to <= 0)
-		return;
 
-	ctx.from = from;
-	ctx.to = to;
-	replace_varno_walker(node, &ctx);
-}
+typedef struct
+{
+	int			from;
+	int			to;
+	int			sublevels_up;
+} ReplaceVarnoContext;
 
-/*
- * Walker function for replace_varno()
- */
 static bool
 replace_varno_walker(Node *node, ReplaceVarnoContext *ctx)
 {
 	if (node == NULL)
 		return false;
-
 	if (IsA(node, Var))
 	{
 		Var		   *var = (Var *) node;
 
-		if (var->varno == ctx->from)
+		if (var->varno == ctx->from &&
+			var->varlevelsup == ctx->sublevels_up)
 		{
 			var->varno = ctx->to;
 			var->varnosyn = ctx->to;
@@ -1501,11 +1461,29 @@ replace_varno_walker(Node *node, ReplaceVarnoContext *ctx)
 	{
 		PlaceHolderVar *phv = (PlaceHolderVar *) node;
 
-		phv->phrels = replace_relid(phv->phrels, ctx->from, ctx->to);
-		phv->phnullingrels = replace_relid(phv->phnullingrels, ctx->from, ctx->to);
+		if (phv->phlevelsup == ctx->sublevels_up)
+		{
+			phv->phrels =
+				replace_relid(phv->phrels, ctx->from, ctx->to);
+			phv->phnullingrels =
+				replace_relid(phv->phnullingrels, ctx->from, ctx->to);
+		}
 
 		/* fall through to recurse into the placeholder's expression */
 	}
+	else if (IsA(node, Query))
+	{
+		/* Recurse into subselects */
+		bool		result;
+
+		ctx->sublevels_up++;
+		result = query_tree_walker((Query *) node,
+								   replace_varno_walker,
+								   (void *) ctx,
+								   QTW_EXAMINE_SORTGROUP);
+		ctx->sublevels_up--;
+		return result;
+	}
 	else if (IsA(node, RestrictInfo))
 	{
 		RestrictInfo *rinfo = (RestrictInfo *) node;
@@ -1517,18 +1495,24 @@ replace_varno_walker(Node *node, ReplaceVarnoContext *ctx)
 		{
 			replace_varno((Node *) rinfo->clause, ctx->from, ctx->to);
 			replace_varno((Node *) rinfo->orclause, ctx->from, ctx->to);
-			rinfo->clause_relids = replace_relid(rinfo->clause_relids, ctx->from, ctx->to);
-			rinfo->left_relids = replace_relid(rinfo->left_relids, ctx->from, ctx->to);
-			rinfo->right_relids = replace_relid(rinfo->right_relids, ctx->from, ctx->to);
+			rinfo->clause_relids =
+				replace_relid(rinfo->clause_relids, ctx->from, ctx->to);
+			rinfo->left_relids =
+				replace_relid(rinfo->left_relids, ctx->from, ctx->to);
+			rinfo->right_relids =
+				replace_relid(rinfo->right_relids, ctx->from, ctx->to);
 		}
 
 		if (is_req_equal)
 			rinfo->required_relids = rinfo->clause_relids;
 		else
-			rinfo->required_relids = replace_relid(rinfo->required_relids, ctx->from, ctx->to);
+			rinfo->required_relids =
+				replace_relid(rinfo->required_relids, ctx->from, ctx->to);
 
-		rinfo->outer_relids = replace_relid(rinfo->outer_relids, ctx->from, ctx->to);
-		rinfo->incompatible_relids = replace_relid(rinfo->incompatible_relids, ctx->from, ctx->to);
+		rinfo->outer_relids =
+			replace_relid(rinfo->outer_relids, ctx->from, ctx->to);
+		rinfo->incompatible_relids =
+			replace_relid(rinfo->incompatible_relids, ctx->from, ctx->to);
 
 		if (rinfo->mergeopfamilies &&
 			bms_get_singleton_member(rinfo->clause_relids, &relid) &&
@@ -1556,7 +1540,30 @@ replace_varno_walker(Node *node, ReplaceVarnoContext *ctx)
 
 		return false;
 	}
-	return expression_tree_walker(node, replace_varno_walker, (void *) ctx);
+
+	return expression_tree_walker(node, replace_varno_walker,
+								  (void *) ctx);
+}
+
+static void
+replace_varno(Node *node, int from, int to)
+{
+	ReplaceVarnoContext ctx;
+
+	if (to <= 0)
+		return;
+
+	ctx.from = from;
+	ctx.to = to;
+	ctx.sublevels_up = 0;
+
+	/*
+	 * Must be prepared to start with a Query or a bare expression tree.
+	 */
+	query_or_expression_tree_walker(node,
+									replace_varno_walker,
+									(void *) &ctx,
+									QTW_EXAMINE_SORTGROUP);
 }
 
 /*
@@ -1748,7 +1755,6 @@ remove_self_join_rel(PlannerInfo *root, PlanRowMark *kmark, PlanRowMark *rmark,
 	int			i;
 	List	   *jinfo_candidates = NIL;
 	List	   *binfo_candidates = NIL;
-	ReplaceVarnoContext ctx = {.from = toRemove->relid,.to = toKeep->relid};
 
 	Assert(toKeep->relid != -1);
 
@@ -1925,8 +1931,7 @@ remove_self_join_rel(PlannerInfo *root, PlanRowMark *kmark, PlanRowMark *rmark,
 	}
 
 	/* Replace varno in all the query structures */
-	query_tree_walker(root->parse, replace_varno_walker, &ctx,
-					  QTW_EXAMINE_SORTGROUP);
+	replace_varno((Node *) root->parse, toRemove->relid, toKeep->relid);
 
 	/* See remove_self_joins_one_group() */
 	Assert(root->parse->resultRelation != toRemove->relid);
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index d560a4a6b9..45f7d1cfc9 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -6314,13 +6314,13 @@ left join int8_tbl z on y.a = z.q1;
 (6 rows)
 
 explain (costs off)
-SELECT * FROM (
-  SELECT t1.*, t2.a AS ax FROM sj t1 JOIN sj t2
-  ON (t1.a = t2.a AND t1.c*t1.c = t2.c+2 AND t2.b IS NULL)
-) AS q1
-LEFT JOIN
-  (SELECT t3.* FROM sj t3, sj t4 WHERE t3.c = t4.c) AS q2
-ON q1.ax = q2.a;
+select * from (
+  select t1.*, t2.a as ax from sj t1 join sj t2
+  on (t1.a = t2.a and t1.c*t1.c = t2.c+2 and t2.b is null)
+) as q1
+left join
+  (select t3.* from sj t3, sj t4 where t3.c = t4.c) as q2
+on q1.ax = q2.a;
                                 QUERY PLAN                                 
 ---------------------------------------------------------------------------
  Nested Loop Left Join
@@ -6349,49 +6349,52 @@ on true;
                ->  Seq Scan on int8_tbl y
 (7 rows)
 
--- Test processing target lists in lateral subqueries
+-- Test that references to the removed rel in lateral subqueries are replaced
+-- correctly after join removal
 explain (verbose, costs off)
-SELECT t3.a FROM sj t1, sj t2,
-LATERAL (SELECT t1.a WHERE t1.a <> 1
-		 GROUP BY (t1.a) HAVING t1.a > 0 ORDER BY t1.a LIMIT 1) t3,
-LATERAL (SELECT t1.a,t3.a WHERE t1.a <> t3.a+t2.a
-		 GROUP BY (t3.a) HAVING t1.a > t3.a*t3.a+t2.a/t1.a LIMIT 2) t4,
-LATERAL (SELECT * FROM sj TABLESAMPLE bernoulli(t1.a/t2.a)
-		 REPEATABLE (t1.a+t2.a)) t5,
-LATERAL generate_series(1, t1.a + t2.a) AS t6
-WHERE t1.a = t2.a;
-                                                          QUERY PLAN                                                           
--------------------------------------------------------------------------------------------------------------------------------
+select t3.a from sj t1
+	join sj t2 on t1.a = t2.a
+	join lateral (select t1.a offset 0) t3 on true;
+             QUERY PLAN             
+------------------------------------
  Nested Loop
    Output: (t2.a)
-   ->  Nested Loop
-         Output: t2.a, (t2.a)
-         ->  Nested Loop
-               Output: t2.a, (t2.a)
-               ->  Nested Loop
-                     Output: t2.a, (t2.a)
-                     ->  Seq Scan on public.sj t2
-                           Output: t2.a, t2.b, t2.c
-                           Filter: (t2.a IS NOT NULL)
-                     ->  Limit
-                           Output: (t2.a)
-                           ->  Group
-                                 Output: t2.a
-                                 ->  Result
-                                       One-Time Filter: ((t2.a <> 1) AND (t2.a > 0))
-               ->  Limit
-                     Output: NULL::integer, ((t2.a))
-                     ->  Group
-                           Output: NULL::integer, (t2.a)
-                           ->  Result
-                                 One-Time Filter: ((t2.a <> ((t2.a) + t2.a)) AND (t2.a > (((t2.a) * (t2.a)) + (t2.a / t2.a))))
-         ->  Sample Scan on public.sj
-               Output: sj.a, sj.b, sj.c
-               Sampling: bernoulli ((t2.a / t2.a)) REPEATABLE ((t2.a + t2.a))
-   ->  Function Scan on pg_catalog.generate_series t6
-         Output: t6.t6
-         Function Call: generate_series(1, (t2.a + t2.a))
-(29 rows)
+   ->  Seq Scan on public.sj t2
+         Output: t2.a, t2.b, t2.c
+         Filter: (t2.a IS NOT NULL)
+   ->  Result
+         Output: t2.a
+(7 rows)
+
+explain (verbose, costs off)
+select t3.a from sj t1
+	join sj t2 on t1.a = t2.a
+	join lateral (select * from (select t1.a offset 0) offset 0) t3 on true;
+             QUERY PLAN             
+------------------------------------
+ Nested Loop
+   Output: (t2.a)
+   ->  Seq Scan on public.sj t2
+         Output: t2.a, t2.b, t2.c
+         Filter: (t2.a IS NOT NULL)
+   ->  Result
+         Output: t2.a
+(7 rows)
+
+explain (verbose, costs off)
+select t4.a from sj t1
+	join sj t2 on t1.a = t2.a
+	join lateral (select t3.a from sj t3, (select t1.a) offset 0) t4 on true;
+             QUERY PLAN             
+------------------------------------
+ Nested Loop
+   Output: t3.a
+   ->  Seq Scan on public.sj t2
+         Output: t2.a, t2.b, t2.c
+         Filter: (t2.a IS NOT NULL)
+   ->  Seq Scan on public.sj t3
+         Output: t3.a
+(7 rows)
 
 -- Check updating of Lateral links from top-level query to the removing relation
 explain (COSTS OFF)
@@ -6412,13 +6415,14 @@ SELECT * FROM pg_am am WHERE am.amname IN (
 (6 rows)
 
 --
--- SJR corner case: uniqueness of an inner is [partially] derived from
+-- SJE corner case: uniqueness of an inner is [partially] derived from
 -- baserestrictinfo clauses.
 -- XXX: We really should allow SJR for these corner cases?
 --
 INSERT INTO sj VALUES (3, 1, 3);
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3;
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3;
           QUERY PLAN          
 ------------------------------
  Nested Loop
@@ -6429,92 +6433,87 @@ explain (costs off) -- Don't remove SJ
          Filter: (a = 3)
 (6 rows)
 
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3; -- Return one row
+-- Return one row
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3;
  a | b | c | a | b | c 
 ---+---+---+---+---+---
  2 | 1 | 1 | 3 | 1 | 3
 (1 row)
 
-explain (costs off) -- Remove SJ, define uniqueness by a constant
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2;
+-- Remove SJ, define uniqueness by a constant
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2;
                QUERY PLAN                
 -----------------------------------------
  Seq Scan on sj j2
    Filter: ((b IS NOT NULL) AND (a = 2))
 (2 rows)
 
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2; -- Return one row
+-- Return one row
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2;
  a | b | c | a | b | c 
 ---+---+---+---+---+---
  2 | 1 | 1 | 2 | 1 | 1
 (1 row)
 
+-- Remove SJ, define uniqueness by a constant expression
 EXPLAIN (COSTS OFF)
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND j1.a = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a
-; -- Remove SJ, define uniqueness by a constant expression
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a;
                                                          QUERY PLAN                                                         
 ----------------------------------------------------------------------------------------------------------------------------
  Seq Scan on sj j2
    Filter: ((b IS NOT NULL) AND (a = (((EXTRACT(dow FROM CURRENT_TIMESTAMP(0)) / '15'::numeric) + '3'::numeric))::integer))
 (2 rows)
 
+-- Return one row
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND j1.a = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a
-; -- Return one row
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a;
  a | b | c | a | b | c 
 ---+---+---+---+---+---
  3 | 1 | 3 | 3 | 1 | 3
 (1 row)
 
-explain (costs off) -- Remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1;
+-- Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1;
                QUERY PLAN                
 -----------------------------------------
  Seq Scan on sj j2
    Filter: ((b IS NOT NULL) AND (a = 1))
 (2 rows)
 
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1; -- Return no rows
+-- Return no rows
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1;
  a | b | c | a | b | c 
 ---+---+---+---+---+---
 (0 rows)
 
-explain (costs off) -- Shuffle a clause. Remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1;
+-- Shuffle a clause. Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1;
                QUERY PLAN                
 -----------------------------------------
  Seq Scan on sj j2
    Filter: ((b IS NOT NULL) AND (a = 1))
 (2 rows)
 
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1; -- Return no rows
+-- Return no rows
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1;
  a | b | c | a | b | c 
 ---+---+---+---+---+---
 (0 rows)
 
 -- SJE Corner case: a 'a.x=a.x' clause, have replaced with 'a.x IS NOT NULL'
 -- after SJ elimination it shouldn't be a mergejoinable clause.
-SELECT t4.*
-FROM (SELECT t1.*, t2.a AS a1 FROM sj t1, sj t2 WHERE t1.b = t2.b) AS t3
-JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42;
- a | b | c 
----+---+---
-(0 rows)
-
 EXPLAIN (COSTS OFF)
 SELECT t4.*
 FROM (SELECT t1.*, t2.a AS a1 FROM sj t1, sj t2 WHERE t1.b = t2.b) AS t3
-JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42
-; -- SJs must be removed.
+JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42;
            QUERY PLAN            
 ---------------------------------
  Nested Loop
@@ -6525,10 +6524,18 @@ JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42
          Filter: (a IS NOT NULL)
 (6 rows)
 
+SELECT t4.*
+FROM (SELECT t1.*, t2.a AS a1 FROM sj t1, sj t2 WHERE t1.b = t2.b) AS t3
+JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42;
+ a | b | c 
+---+---+---
+(0 rows)
+
 -- Functional index
 CREATE UNIQUE INDEX sj_fn_idx ON sj((a * a));
-explain (costs off) -- Remove SJ
-	SELECT * FROM sj j1, sj j2
+-- Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND j1.a*j1.a = 1 AND j2.a*j2.a = 1;
                   QUERY PLAN                   
 -----------------------------------------------
@@ -6536,8 +6543,9 @@ explain (costs off) -- Remove SJ
    Filter: ((b IS NOT NULL) AND ((a * a) = 1))
 (2 rows)
 
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND j1.a*j1.a = 1 AND j2.a*j2.a = 2;
           QUERY PLAN           
 -------------------------------
@@ -6549,48 +6557,48 @@ explain (costs off) -- Don't remove SJ
          Filter: ((a * a) = 2)
 (6 rows)
 
+-- Restriction contains expressions in both sides, Remove SJ.
 EXPLAIN (COSTS OFF)
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND (j1.a*j1.a) = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a)
-; -- Restriction contains expressions in both sides, Remove SJ.
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a);
                                                             QUERY PLAN                                                            
 ----------------------------------------------------------------------------------------------------------------------------------
  Seq Scan on sj j2
    Filter: ((b IS NOT NULL) AND ((a * a) = (((EXTRACT(dow FROM CURRENT_TIMESTAMP(0)) / '15'::numeric) + '3'::numeric))::integer))
 (2 rows)
 
+-- Empty set of rows should be returned
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND (j1.a*j1.a) = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a)
-; -- Empty set of rows should be returned
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a);
  a | b | c | a | b | c 
 ---+---+---+---+---+---
 (0 rows)
 
+-- Restriction contains volatile function - disable SJR feature.
 EXPLAIN (COSTS OFF)
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
-  AND (j1.a*j1.a) = (random()/3 + 3)::int
-  AND (random()/3 + 3)::int = (j2.a*j2.a)
-; -- Restriction contains volatile function - disable SJR feature.
-                                             QUERY PLAN                                              
------------------------------------------------------------------------------------------------------
+  AND (j1.a*j1.c/3) = (random()/3 + 3)::int
+  AND (random()/3 + 3)::int = (j2.a*j2.c/3);
+                                                QUERY PLAN                                                 
+-----------------------------------------------------------------------------------------------------------
  Nested Loop
    Join Filter: (j1.b = j2.b)
    ->  Seq Scan on sj j1
-         Filter: ((a * a) = (((random() / '3'::double precision) + '3'::double precision))::integer)
+         Filter: (((a * c) / 3) = (((random() / '3'::double precision) + '3'::double precision))::integer)
    ->  Seq Scan on sj j2
-         Filter: ((((random() / '3'::double precision) + '3'::double precision))::integer = (a * a))
+         Filter: ((((random() / '3'::double precision) + '3'::double precision))::integer = ((a * c) / 3))
 (6 rows)
 
+-- Return one row
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND (j1.a*j1.c/3) = (random()/3 + 3)::int
-  AND (random()/3 + 3)::int = (j2.a*j2.c/3)
-; -- Return one row
+  AND (random()/3 + 3)::int = (j2.a*j2.c/3);
  a | b | c | a | b | c 
 ---+---+---+---+---+---
  3 | 1 | 3 | 3 | 1 | 3
@@ -6598,8 +6606,9 @@ WHERE j1.b = j2.b
 
 -- Multiple filters
 CREATE UNIQUE INDEX sj_temp_idx1 ON sj(a,b,c);
-explain (costs off) -- Remove SJ
-	SELECT * FROM sj j1, sj j2
+-- Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND j1.a = 2 AND j1.c = 3 AND j2.a = 2 AND 3 = j2.c;
                      QUERY PLAN                      
 -----------------------------------------------------
@@ -6607,7 +6616,8 @@ explain (costs off) -- Remove SJ
    Filter: ((b IS NOT NULL) AND (a = 2) AND (c = 3))
 (2 rows)
 
-explain (costs off) -- Don't remove SJ
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
 	SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND 2 = j1.a AND j1.c = 3 AND j2.a = 1 AND 3 = j2.c;
               QUERY PLAN               
@@ -6621,8 +6631,9 @@ explain (costs off) -- Don't remove SJ
 (6 rows)
 
 CREATE UNIQUE INDEX sj_temp_idx ON sj(a,b);
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2;
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2;
           QUERY PLAN          
 ------------------------------
  Nested Loop
@@ -6632,8 +6643,9 @@ explain (costs off) -- Don't remove SJ
    ->  Seq Scan on sj j2
 (5 rows)
 
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 2 = j2.a;
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 2 = j2.a;
           QUERY PLAN          
 ------------------------------
  Nested Loop
@@ -6643,8 +6655,9 @@ explain (costs off) -- Don't remove SJ
    ->  Seq Scan on sj j1
 (5 rows)
 
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND (j1.a = 1 OR j2.a = 1);
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND (j1.a = 1 OR j2.a = 1);
                           QUERY PLAN                           
 ---------------------------------------------------------------
  Nested Loop
@@ -6658,7 +6671,7 @@ DROP INDEX sj_fn_idx, sj_temp_idx1, sj_temp_idx;
 -- Test that OR predicated are updated correctly after join removal
 CREATE TABLE tab_with_flag ( id INT PRIMARY KEY, is_flag SMALLINT);
 CREATE INDEX idx_test_is_flag ON tab_with_flag (is_flag);
-explain (costs off)
+EXPLAIN (COSTS OFF)
 SELECT COUNT(*) FROM tab_with_flag
 WHERE
 	(is_flag IS NULL OR is_flag = 0)
@@ -6787,7 +6800,7 @@ reset join_collapse_limit;
 reset enable_seqscan;
 -- Check that clauses from the join filter list is not lost on the self-join removal
 CREATE TABLE emp1 (id SERIAL PRIMARY KEY NOT NULL, code int);
-explain (verbose, costs off)
+EXPLAIN (VERBOSE, COSTS OFF)
 SELECT * FROM emp1 e1, emp1 e2 WHERE e1.id = e2.id AND e2.code <> e1.code;
                 QUERY PLAN                
 ------------------------------------------
@@ -6799,7 +6812,7 @@ SELECT * FROM emp1 e1, emp1 e2 WHERE e1.id = e2.id AND e2.code <> e1.code;
 -- Shuffle self-joined relations. Only in the case of iterative deletion
 -- attempts explains of these queries will be identical.
 CREATE UNIQUE INDEX ON emp1((id*id));
-explain (costs off)
+EXPLAIN (COSTS OFF)
 SELECT count(*) FROM emp1 c1, emp1 c2, emp1 c3
 WHERE c1.id=c2.id AND c1.id*c2.id=c3.id*c3.id;
                QUERY PLAN                
@@ -6809,7 +6822,7 @@ WHERE c1.id=c2.id AND c1.id*c2.id=c3.id*c3.id;
          Filter: ((id * id) IS NOT NULL)
 (3 rows)
 
-explain (costs off)
+EXPLAIN (COSTS OFF)
 SELECT count(*) FROM emp1 c1, emp1 c2, emp1 c3
 WHERE c1.id=c3.id AND c1.id*c3.id=c2.id*c2.id;
                QUERY PLAN                
@@ -6819,7 +6832,7 @@ WHERE c1.id=c3.id AND c1.id*c3.id=c2.id*c2.id;
          Filter: ((id * id) IS NOT NULL)
 (3 rows)
 
-explain (costs off)
+EXPLAIN (COSTS OFF)
 SELECT count(*) FROM emp1 c1, emp1 c2, emp1 c3
 WHERE c3.id=c2.id AND c3.id*c2.id=c1.id*c1.id;
                QUERY PLAN                
@@ -6830,7 +6843,7 @@ WHERE c3.id=c2.id AND c3.id*c2.id=c1.id*c1.id;
 (3 rows)
 
 -- Check the usage of a parse tree by the set operations (bug #18170)
-explain (costs off)
+EXPLAIN (COSTS OFF)
 SELECT c1.code FROM emp1 c1 LEFT JOIN emp1 c2 ON c1.id = c2.id
 WHERE c2.id IS NOT NULL
 EXCEPT ALL
@@ -6928,7 +6941,7 @@ select * from emp1 t1
 (5 rows)
 
 -- Check that SJE doesn't replace the target relation
-explain (costs off)
+EXPLAIN (COSTS OFF)
 WITH t1 AS (SELECT * FROM emp1)
 UPDATE emp1 SET code = t1.code + 1 FROM t1
 WHERE t1.id = emp1.id RETURNING emp1.id, emp1.code, t1.code;
@@ -7077,7 +7090,7 @@ where t1.b = t2.b and t2.a = 3 and t1.a = 3
 (3 rows)
 
 -- Join qual isn't mergejoinable, but inner is unique.
-explain (COSTS OFF)
+EXPLAIN (COSTS OFF)
 SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a AND n2.a = 1;
           QUERY PLAN           
 -------------------------------
@@ -7088,9 +7101,9 @@ SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a AND n2.a = 1;
    ->  Seq Scan on sj n1
 (5 rows)
 
-explain (COSTS OFF)
+EXPLAIN (COSTS OFF)
 SELECT * FROM
-	(SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a) q0, sl
+(SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a) q0, sl
 WHERE q0.a = 1;
           QUERY PLAN           
 -------------------------------
@@ -7103,20 +7116,6 @@ WHERE q0.a = 1;
    ->  Seq Scan on sj n1
 (7 rows)
 
---
----- Only one side is unique
---select * from sl t1, sl t2 where t1.a = t2.a and t1.b = 1;
---select * from sl t1, sl t2 where t1.a = t2.a and t2.b = 1;
---
----- Several uniques indexes match, and we select a different one
----- for each side, so the join is not removed
---create table sm(a int unique, b int unique, c int unique);
---explain (costs off)
---select * from sm m, sm n where m.a = n.b and m.c = n.c;
---explain (costs off)
---select * from sm m, sm n where m.a = n.c and m.b = n.b;
---explain (costs off)
---select * from sm m, sm n where m.c = n.b and m.a = n.a;
 -- Check optimization disabling if it will violate special join conditions.
 -- Two identical joined relations satisfies self join removal conditions but
 -- stay in different special join infos.
@@ -7175,7 +7174,8 @@ ON sj_t1.id = _t2t3t4.id;
 --
 -- Test RowMarks-related code
 --
-EXPLAIN (COSTS OFF) -- Both sides have explicit LockRows marks
+-- Both sides have explicit LockRows marks
+EXPLAIN (COSTS OFF)
 SELECT a1.a FROM sj a1,sj a2 WHERE (a1.a=a2.a) FOR UPDATE;
            QUERY PLAN            
 ---------------------------------
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 9341f80bbc..e6ecfe36af 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -2390,13 +2390,13 @@ select * from sj x join sj y on x.a = y.a
 left join int8_tbl z on y.a = z.q1;
 
 explain (costs off)
-SELECT * FROM (
-  SELECT t1.*, t2.a AS ax FROM sj t1 JOIN sj t2
-  ON (t1.a = t2.a AND t1.c*t1.c = t2.c+2 AND t2.b IS NULL)
-) AS q1
-LEFT JOIN
-  (SELECT t3.* FROM sj t3, sj t4 WHERE t3.c = t4.c) AS q2
-ON q1.ax = q2.a;
+select * from (
+  select t1.*, t2.a as ax from sj t1 join sj t2
+  on (t1.a = t2.a and t1.c*t1.c = t2.c+2 and t2.b is null)
+) as q1
+left join
+  (select t3.* from sj t3, sj t4 where t3.c = t4.c) as q2
+on q1.ax = q2.a;
 
 -- Test that placeholders are updated correctly after join removal
 explain (costs off)
@@ -2406,17 +2406,22 @@ left join (select coalesce(y.q1, 1) from int8_tbl y
 	on true) z
 on true;
 
--- Test processing target lists in lateral subqueries
+-- Test that references to the removed rel in lateral subqueries are replaced
+-- correctly after join removal
 explain (verbose, costs off)
-SELECT t3.a FROM sj t1, sj t2,
-LATERAL (SELECT t1.a WHERE t1.a <> 1
-		 GROUP BY (t1.a) HAVING t1.a > 0 ORDER BY t1.a LIMIT 1) t3,
-LATERAL (SELECT t1.a,t3.a WHERE t1.a <> t3.a+t2.a
-		 GROUP BY (t3.a) HAVING t1.a > t3.a*t3.a+t2.a/t1.a LIMIT 2) t4,
-LATERAL (SELECT * FROM sj TABLESAMPLE bernoulli(t1.a/t2.a)
-		 REPEATABLE (t1.a+t2.a)) t5,
-LATERAL generate_series(1, t1.a + t2.a) AS t6
-WHERE t1.a = t2.a;
+select t3.a from sj t1
+	join sj t2 on t1.a = t2.a
+	join lateral (select t1.a offset 0) t3 on true;
+
+explain (verbose, costs off)
+select t3.a from sj t1
+	join sj t2 on t1.a = t2.a
+	join lateral (select * from (select t1.a offset 0) offset 0) t3 on true;
+
+explain (verbose, costs off)
+select t4.a from sj t1
+	join sj t2 on t1.a = t2.a
+	join lateral (select t3.a from sj t3, (select t1.a) offset 0) t4 on true;
 
 -- Check updating of Lateral links from top-level query to the removing relation
 explain (COSTS OFF)
@@ -2428,109 +2433,129 @@ SELECT * FROM pg_am am WHERE am.amname IN (
 );
 
 --
--- SJR corner case: uniqueness of an inner is [partially] derived from
+-- SJE corner case: uniqueness of an inner is [partially] derived from
 -- baserestrictinfo clauses.
 -- XXX: We really should allow SJR for these corner cases?
 --
 
 INSERT INTO sj VALUES (3, 1, 3);
 
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3;
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3; -- Return one row
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3;
+-- Return one row
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 3;
 
-explain (costs off) -- Remove SJ, define uniqueness by a constant
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2;
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2; -- Return one row
+-- Remove SJ, define uniqueness by a constant
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2;
+-- Return one row
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2 AND j2.a = 2;
 
+-- Remove SJ, define uniqueness by a constant expression
 EXPLAIN (COSTS OFF)
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND j1.a = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a
-; -- Remove SJ, define uniqueness by a constant expression
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a;
+-- Return one row
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND j1.a = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a
-; -- Return one row
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = j2.a;
 
-explain (costs off) -- Remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1;
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1; -- Return no rows
+-- Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1;
+-- Return no rows
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 1 AND j2.a = 1;
 
-explain (costs off) -- Shuffle a clause. Remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1;
-SELECT * FROM sj j1, sj j2
-WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1; -- Return no rows
+-- Shuffle a clause. Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1;
+-- Return no rows
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 1 = j1.a AND j2.a = 1;
 
 -- SJE Corner case: a 'a.x=a.x' clause, have replaced with 'a.x IS NOT NULL'
 -- after SJ elimination it shouldn't be a mergejoinable clause.
+EXPLAIN (COSTS OFF)
 SELECT t4.*
 FROM (SELECT t1.*, t2.a AS a1 FROM sj t1, sj t2 WHERE t1.b = t2.b) AS t3
 JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42;
-EXPLAIN (COSTS OFF)
 SELECT t4.*
 FROM (SELECT t1.*, t2.a AS a1 FROM sj t1, sj t2 WHERE t1.b = t2.b) AS t3
-JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42
-; -- SJs must be removed.
+JOIN sj t4 ON (t4.a = t3.a) WHERE t3.a1 = 42;
 
 -- Functional index
 CREATE UNIQUE INDEX sj_fn_idx ON sj((a * a));
-explain (costs off) -- Remove SJ
-	SELECT * FROM sj j1, sj j2
+
+-- Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND j1.a*j1.a = 1 AND j2.a*j2.a = 1;
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND j1.a*j1.a = 1 AND j2.a*j2.a = 2;
+
+-- Restriction contains expressions in both sides, Remove SJ.
 EXPLAIN (COSTS OFF)
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND (j1.a*j1.a) = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a)
-; -- Restriction contains expressions in both sides, Remove SJ.
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a);
+-- Empty set of rows should be returned
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND (j1.a*j1.a) = (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int
-  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a)
-; -- Empty set of rows should be returned
+  AND (EXTRACT(DOW FROM current_timestamp(0))/15 + 3)::int = (j2.a*j2.a);
+
+-- Restriction contains volatile function - disable SJR feature.
 EXPLAIN (COSTS OFF)
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
-  AND (j1.a*j1.a) = (random()/3 + 3)::int
-  AND (random()/3 + 3)::int = (j2.a*j2.a)
-; -- Restriction contains volatile function - disable SJR feature.
+  AND (j1.a*j1.c/3) = (random()/3 + 3)::int
+  AND (random()/3 + 3)::int = (j2.a*j2.c/3);
+-- Return one row
 SELECT * FROM sj j1, sj j2
 WHERE j1.b = j2.b
   AND (j1.a*j1.c/3) = (random()/3 + 3)::int
-  AND (random()/3 + 3)::int = (j2.a*j2.c/3)
-; -- Return one row
+  AND (random()/3 + 3)::int = (j2.a*j2.c/3);
 
 -- Multiple filters
 CREATE UNIQUE INDEX sj_temp_idx1 ON sj(a,b,c);
-explain (costs off) -- Remove SJ
-	SELECT * FROM sj j1, sj j2
+
+-- Remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND j1.a = 2 AND j1.c = 3 AND j2.a = 2 AND 3 = j2.c;
-explain (costs off) -- Don't remove SJ
+
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
 	SELECT * FROM sj j1, sj j2
 	WHERE j1.b = j2.b AND 2 = j1.a AND j1.c = 3 AND j2.a = 1 AND 3 = j2.c;
 
 CREATE UNIQUE INDEX sj_temp_idx ON sj(a,b);
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2;
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 2 = j2.a;
-explain (costs off) -- Don't remove SJ
-	SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND (j1.a = 1 OR j2.a = 1);
+
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND j1.a = 2;
+
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND 2 = j2.a;
+
+-- Don't remove SJ
+EXPLAIN (COSTS OFF)
+SELECT * FROM sj j1, sj j2 WHERE j1.b = j2.b AND (j1.a = 1 OR j2.a = 1);
+
 DROP INDEX sj_fn_idx, sj_temp_idx1, sj_temp_idx;
 
 -- Test that OR predicated are updated correctly after join removal
 CREATE TABLE tab_with_flag ( id INT PRIMARY KEY, is_flag SMALLINT);
 CREATE INDEX idx_test_is_flag ON tab_with_flag (is_flag);
-explain (costs off)
+
+EXPLAIN (COSTS OFF)
 SELECT COUNT(*) FROM tab_with_flag
 WHERE
 	(is_flag IS NULL OR is_flag = 0)
@@ -2581,24 +2606,27 @@ reset enable_seqscan;
 
 -- Check that clauses from the join filter list is not lost on the self-join removal
 CREATE TABLE emp1 (id SERIAL PRIMARY KEY NOT NULL, code int);
-explain (verbose, costs off)
+EXPLAIN (VERBOSE, COSTS OFF)
 SELECT * FROM emp1 e1, emp1 e2 WHERE e1.id = e2.id AND e2.code <> e1.code;
 
 -- Shuffle self-joined relations. Only in the case of iterative deletion
 -- attempts explains of these queries will be identical.
 CREATE UNIQUE INDEX ON emp1((id*id));
-explain (costs off)
+
+EXPLAIN (COSTS OFF)
 SELECT count(*) FROM emp1 c1, emp1 c2, emp1 c3
 WHERE c1.id=c2.id AND c1.id*c2.id=c3.id*c3.id;
-explain (costs off)
+
+EXPLAIN (COSTS OFF)
 SELECT count(*) FROM emp1 c1, emp1 c2, emp1 c3
 WHERE c1.id=c3.id AND c1.id*c3.id=c2.id*c2.id;
-explain (costs off)
+
+EXPLAIN (COSTS OFF)
 SELECT count(*) FROM emp1 c1, emp1 c2, emp1 c3
 WHERE c3.id=c2.id AND c3.id*c2.id=c1.id*c1.id;
 
 -- Check the usage of a parse tree by the set operations (bug #18170)
-explain (costs off)
+EXPLAIN (COSTS OFF)
 SELECT c1.code FROM emp1 c1 LEFT JOIN emp1 c2 ON c1.id = c2.id
 WHERE c2.id IS NOT NULL
 EXCEPT ALL
@@ -2637,14 +2665,17 @@ select * from emp1 t1
     left join emp1 t3 on t1.id > 1 and t1.id < 2;
 
 -- Check that SJE doesn't replace the target relation
-explain (costs off)
+EXPLAIN (COSTS OFF)
 WITH t1 AS (SELECT * FROM emp1)
 UPDATE emp1 SET code = t1.code + 1 FROM t1
 WHERE t1.id = emp1.id RETURNING emp1.id, emp1.code, t1.code;
+
 INSERT INTO emp1 VALUES (1, 1), (2, 1);
+
 WITH t1 AS (SELECT * FROM emp1)
 UPDATE emp1 SET code = t1.code + 1 FROM t1
 WHERE t1.id = emp1.id RETURNING emp1.id, emp1.code, t1.code;
+
 TRUNCATE emp1;
 
 EXPLAIN (COSTS OFF)
@@ -2707,28 +2738,14 @@ where t1.b = t2.b and t2.a = 3 and t1.a = 3
   and t1.a IS NOT NULL and t2.a IS NOT NULL;
 
 -- Join qual isn't mergejoinable, but inner is unique.
-explain (COSTS OFF)
+EXPLAIN (COSTS OFF)
 SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a AND n2.a = 1;
-explain (COSTS OFF)
+
+EXPLAIN (COSTS OFF)
 SELECT * FROM
-	(SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a) q0, sl
+(SELECT n2.a FROM sj n1, sj n2 WHERE n1.a <> n2.a) q0, sl
 WHERE q0.a = 1;
 
---
----- Only one side is unique
---select * from sl t1, sl t2 where t1.a = t2.a and t1.b = 1;
---select * from sl t1, sl t2 where t1.a = t2.a and t2.b = 1;
---
----- Several uniques indexes match, and we select a different one
----- for each side, so the join is not removed
---create table sm(a int unique, b int unique, c int unique);
---explain (costs off)
---select * from sm m, sm n where m.a = n.b and m.c = n.c;
---explain (costs off)
---select * from sm m, sm n where m.a = n.c and m.b = n.b;
---explain (costs off)
---select * from sm m, sm n where m.c = n.b and m.a = n.a;
-
 -- Check optimization disabling if it will violate special join conditions.
 -- Two identical joined relations satisfies self join removal conditions but
 -- stay in different special join infos.
@@ -2763,7 +2780,8 @@ ON sj_t1.id = _t2t3t4.id;
 -- Test RowMarks-related code
 --
 
-EXPLAIN (COSTS OFF) -- Both sides have explicit LockRows marks
+-- Both sides have explicit LockRows marks
+EXPLAIN (COSTS OFF)
 SELECT a1.a FROM sj a1,sj a2 WHERE (a1.a=a2.a) FOR UPDATE;
 
 reset enable_hashjoin;
-- 
2.31.0