diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 37e1d26bda7..f3e7018ed2a 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -2461,7 +2461,8 @@ set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) if (ndx >= list_length(cteroot->cte_plan_ids)) elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename); plan_id = list_nth_int(cteroot->cte_plan_ids, ndx); - Assert(plan_id > 0); + if (plan_id <= 0) + elog(ERROR, "no plan was made for CTE \"%s\"", rte->ctename); cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1); /* Mark rel with estimated output rows, width, etc */ diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index c04b21553d1..a2101fb3fcb 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -3862,7 +3862,8 @@ create_ctescan_plan(PlannerInfo *root, Path *best_path, if (ndx >= list_length(cteroot->cte_plan_ids)) elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename); plan_id = list_nth_int(cteroot->cte_plan_ids, ndx); - Assert(plan_id > 0); + if (plan_id <= 0) + elog(ERROR, "no plan was made for CTE \"%s\"", rte->ctename); foreach(lc, cteroot->init_plans) { ctesplan = (SubPlan *) lfirst(lc); diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index cb3dde946f5..0ee36b95004 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -61,7 +61,6 @@ typedef struct inline_cte_walker_context { const char *ctename; /* name and relative level of target CTE */ int levelsup; - int refcount; /* number of remaining references */ Query *ctequery; /* query to substitute */ } inline_cte_walker_context; @@ -1157,13 +1156,9 @@ inline_cte(PlannerInfo *root, CommonTableExpr *cte) context.ctename = cte->ctename; /* Start at levelsup = -1 because we'll immediately increment it */ context.levelsup = -1; - context.refcount = cte->cterefcount; context.ctequery = castNode(Query, cte->ctequery); (void) inline_cte_walker((Node *) root->parse, &context); - - /* Assert we replaced all references */ - Assert(context.refcount == 0); } static bool @@ -1226,9 +1221,6 @@ inline_cte_walker(Node *node, inline_cte_walker_context *context) rte->coltypes = NIL; rte->coltypmods = NIL; rte->colcollations = NIL; - - /* Count the number of replacements we've done */ - context->refcount--; } return false; diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h index 8ee40cc68c2..f16466a0df1 100644 --- a/src/include/nodes/pathnodes.h +++ b/src/include/nodes/pathnodes.h @@ -240,7 +240,8 @@ struct PlannerInfo List *init_plans; /* init SubPlans for query */ - List *cte_plan_ids; /* per-CTE-item list of subplan IDs */ + List *cte_plan_ids; /* per-CTE-item list of subplan IDs (or -1 if + * no subplan was made for that CTE) */ List *multiexpr_params; /* List of Lists of Params for MULTIEXPR * subquery outputs */ diff --git a/src/test/regress/expected/with.out b/src/test/regress/expected/with.out index d17da5c32ad..b7f02d6de1b 100644 --- a/src/test/regress/expected/with.out +++ b/src/test/regress/expected/with.out @@ -2504,6 +2504,70 @@ SELECT * FROM bug6051_3; --- (0 rows) +-- check case where CTE reference is removed due to optimization +EXPLAIN (VERBOSE, COSTS OFF) +SELECT q1 FROM +( + WITH t_cte AS (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + QUERY PLAN +-------------------------------------- + Subquery Scan on ss + Output: ss.q1 + -> Seq Scan on public.int8_tbl i8 + Output: i8.q1, NULL::bigint +(4 rows) + +SELECT q1 FROM +( + WITH t_cte AS (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + q1 +------------------ + 123 + 123 + 4567890123456789 + 4567890123456789 + 4567890123456789 +(5 rows) + +EXPLAIN (VERBOSE, COSTS OFF) +SELECT q1 FROM +( + WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + QUERY PLAN +--------------------------------------------- + Subquery Scan on ss + Output: ss.q1 + -> Seq Scan on public.int8_tbl i8 + Output: i8.q1, NULL::bigint + CTE t_cte + -> Seq Scan on public.int8_tbl t + Output: t.q1, t.q2 +(7 rows) + +SELECT q1 FROM +( + WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + q1 +------------------ + 123 + 123 + 4567890123456789 + 4567890123456789 + 4567890123456789 +(5 rows) + -- a truly recursive CTE in the same list WITH RECURSIVE t(a) AS ( SELECT 0 diff --git a/src/test/regress/sql/with.sql b/src/test/regress/sql/with.sql index 2b99e43a0b2..2be7e0866ac 100644 --- a/src/test/regress/sql/with.sql +++ b/src/test/regress/sql/with.sql @@ -1173,6 +1173,37 @@ COMMIT; SELECT * FROM bug6051_3; +-- check case where CTE reference is removed due to optimization +EXPLAIN (VERBOSE, COSTS OFF) +SELECT q1 FROM +( + WITH t_cte AS (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + +SELECT q1 FROM +( + WITH t_cte AS (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + +EXPLAIN (VERBOSE, COSTS OFF) +SELECT q1 FROM +( + WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + +SELECT q1 FROM +( + WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) + SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub + FROM int8_tbl i8 +) ss; + -- a truly recursive CTE in the same list WITH RECURSIVE t(a) AS ( SELECT 0