Fix the way SJE removes references from PHVs

akorotkov · akorotkov · commit b44a1708abe3 · 2023-11-09T14:25:13.000+02:00
Add missing replacement of relids in phv->phexpr. Also, remove extra replace_relid() over phv->phrels. Reported-by: Zuming Jiang Bug: #18187 Discussion: https://postgr.es/m/flat/18187-831da249cbd2ff8e%40postgresql.org Author: Richard Guo Reviewed-by: Andrei Lepikhov
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c
@@ -474,9 +474,9 @@ remove_rel_from_query(PlannerInfo *root, RelOptInfo *rel,
 			/* ph_needed might or might not become empty */
 			phv->phrels = replace_relid(phv->phrels, relid, subst);
 			phv->phrels = replace_relid(phv->phrels, ojrelid, subst);
-			phinfo->ph_lateral = replace_relid(phinfo->ph_lateral, relid, subst);
-			phinfo->ph_var->phrels = replace_relid(phinfo->ph_var->phrels, relid, subst);
 			Assert(!bms_is_empty(phv->phrels));
+			replace_varno((Node *) phv->phexpr, relid, subst);
+			phinfo->ph_lateral = replace_relid(phinfo->ph_lateral, relid, subst);
 			Assert(phv->phnullingrels == NULL); /* no need to adjust */
 		}
 	}
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
@@ -6776,6 +6776,25 @@ SELECT c3.code FROM emp1 c3;
                ->  Seq Scan on emp1 c3
 (7 rows)
 
+-- Check that SJE removes references from PHVs correctly
+explain (costs off)
+select * from emp1 t1 left join
+    (select coalesce(t3.code, 1) from emp1 t2
+        left join (emp1 t3 join emp1 t4 on t3.id = t4.id)
+        on true)
+on true;
+                     QUERY PLAN                     
+----------------------------------------------------
+ Nested Loop Left Join
+   ->  Seq Scan on emp1 t1
+   ->  Materialize
+         ->  Nested Loop Left Join
+               ->  Seq Scan on emp1 t2
+               ->  Materialize
+                     ->  Seq Scan on emp1 t4
+                           Filter: (id IS NOT NULL)
+(8 rows)
+
 -- We can remove the join even if we find the join can't duplicate rows and
 -- the base quals of each side are different.  In the following case we end up
 -- moving quals over to s1 to make it so it can't match any rows.
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
@@ -2580,6 +2580,14 @@ WHERE c2.id IS NOT NULL
 EXCEPT ALL
 SELECT c3.code FROM emp1 c3;
 
+-- Check that SJE removes references from PHVs correctly
+explain (costs off)
+select * from emp1 t1 left join
+    (select coalesce(t3.code, 1) from emp1 t2
+        left join (emp1 t3 join emp1 t4 on t3.id = t4.id)
+        on true)
+on true;
+
 -- We can remove the join even if we find the join can't duplicate rows and
 -- the base quals of each side are different.  In the following case we end up
 -- moving quals over to s1 to make it so it can't match any rows.

Original file line number	Diff line number	Diff line change
`@@ -474,9 +474,9 @@ remove_rel_from_query(PlannerInfo root, RelOptInfo rel,`
`474`	`474`	`/* ph_needed might or might not become empty */`
`475`	`475`	`phv->phrels = replace_relid(phv->phrels, relid, subst);`
`476`	`476`	`phv->phrels = replace_relid(phv->phrels, ojrelid, subst);`
`477`		`- phinfo->ph_lateral = replace_relid(phinfo->ph_lateral, relid, subst);`
`478`		`- phinfo->ph_var->phrels = replace_relid(phinfo->ph_var->phrels, relid, subst);`
`479`	`477`	`Assert(!bms_is_empty(phv->phrels));`
	`478`	`+ replace_varno((Node *) phv->phexpr, relid, subst);`
	`479`	`+ phinfo->ph_lateral = replace_relid(phinfo->ph_lateral, relid, subst);`
`480`	`480`	`Assert(phv->phnullingrels == NULL); /* no need to adjust */`
`481`	`481`	`}`
`482`	`482`	`}`