diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 73ff40721c..57262f9c64 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -2435,8 +2435,13 @@ pullup_replace_vars_callback(Var *var, else if (newnode && IsA(newnode, PlaceHolderVar) && ((PlaceHolderVar *) newnode)->phlevelsup == 0) { - /* No need to wrap a PlaceHolderVar with another one, either */ - wrap = false; + /* The same rules apply for a PlaceHolderVar */ + if (rcon->target_rte->lateral && + !bms_is_subset(((PlaceHolderVar *) newnode)->phrels, + rcon->relids)) + wrap = true; + else + wrap = false; } else { diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out index e3f29b1d16..3715ae491d 100644 --- a/src/test/regress/expected/join.out +++ b/src/test/regress/expected/join.out @@ -7013,6 +7013,33 @@ select * from Output: (COALESCE((COALESCE(b.q2, '42'::bigint)), d.q2)) (24 rows) +-- another case requiring nested PlaceHolderVars +explain (verbose, costs off) +select * from + (select 0 as val0) as ss0 + left join (select 1 as val) as ss1 on true + left join lateral (select ss1.val as val_filtered where false) as ss2 on true; + QUERY PLAN +-------------------------------- + Nested Loop Left Join + Output: 0, (1), ((1)) + Join Filter: false + -> Result + Output: 1 + -> Result + Output: (1) + One-Time Filter: false +(8 rows) + +select * from + (select 0 as val0) as ss0 + left join (select 1 as val) as ss1 on true + left join lateral (select ss1.val as val_filtered where false) as ss2 on true; + val0 | val | val_filtered +------+-----+-------------- + 0 | 1 | +(1 row) + -- case that breaks the old ph_may_need optimization explain (verbose, costs off) select c.*,a.*,ss1.q1,ss2.q1,ss3.* from diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql index 8bf18f11bc..3443b21e6b 100644 --- a/src/test/regress/sql/join.sql +++ b/src/test/regress/sql/join.sql @@ -2522,6 +2522,18 @@ select * from ) on c.q2 = ss2.q1, lateral (select ss2.y offset 0) ss3; +-- another case requiring nested PlaceHolderVars +explain (verbose, costs off) +select * from + (select 0 as val0) as ss0 + left join (select 1 as val) as ss1 on true + left join lateral (select ss1.val as val_filtered where false) as ss2 on true; + +select * from + (select 0 as val0) as ss0 + left join (select 1 as val) as ss1 on true + left join lateral (select ss1.val as val_filtered where false) as ss2 on true; + -- case that breaks the old ph_may_need optimization explain (verbose, costs off) select c.*,a.*,ss1.q1,ss2.q1,ss3.* from