diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c index f177eba..6d456f6 100644 --- a/contrib/pg_stat_statements/pg_stat_statements.c +++ b/contrib/pg_stat_statements/pg_stat_statements.c @@ -2925,6 +2925,7 @@ JumbleExpr(pgssJumbleState *jstate, Node *node) /* we store the string name because RTE_CTE RTEs need it */ APP_JUMB_STRING(cte->ctename); + APP_JUMB(cte->ctematerialized); JumbleQuery(jstate, castNode(Query, cte->ctequery)); } break; diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index bb92d9d..8c26dd1 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -1888,7 +1888,7 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t -- join in CTE EXPLAIN (VERBOSE, COSTS OFF) -WITH t (c1_1, c1_3, c2_1) AS (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; +WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------- Limit @@ -1905,7 +1905,7 @@ WITH t (c1_1, c1_3, c2_1) AS (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 Output: t.c1_1, t.c2_1, t.c1_3 (12 rows) -WITH t (c1_1, c1_3, c2_1) AS (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; +WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; c1_1 | c2_1 ------+------ 101 | 101 diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql index f438165..56602a1 100644 --- a/contrib/postgres_fdw/sql/postgres_fdw.sql +++ b/contrib/postgres_fdw/sql/postgres_fdw.sql @@ -493,8 +493,8 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE; -- join in CTE EXPLAIN (VERBOSE, COSTS OFF) -WITH t (c1_1, c1_3, c2_1) AS (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; -WITH t (c1_1, c1_3, c2_1) AS (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; +WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; +WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10; -- ctid with whole-row reference EXPLAIN (VERBOSE, COSTS OFF) SELECT t1.ctid, t1, t2, t1.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10; diff --git a/doc/src/sgml/queries.sgml b/doc/src/sgml/queries.sgml index 88bc189..92f180c 100644 --- a/doc/src/sgml/queries.sgml +++ b/doc/src/sgml/queries.sgml @@ -2199,6 +2199,8 @@ SELECT n FROM t LIMIT 100; + TODO: Update this for inlining and MATERIALIZED. + A useful property of WITH queries is that they are evaluated only once per execution of the parent query, even if they are referred to more than once by the parent query or sibling WITH queries. diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 4db8142..92ede4f 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -72,7 +72,7 @@ SELECT [ ALL | DISTINCT [ ON ( expressionand with_query is: - with_query_name [ ( column_name [, ...] ) ] AS ( select | values | insert | update | delete ) + with_query_name [ ( column_name [, ...] ) ] AS [ MATERIALIZED ] ( select | values | insert | update | delete ) TABLE [ ONLY ] table_name [ * ] @@ -273,6 +273,8 @@ TABLE [ ONLY ] table_name [ * ] + TODO: Update this for inlining and MATERIALIZED. + A key property of WITH queries is that they are evaluated only once per execution of the primary query, even if the primary query refers to them more than once. diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index 3eb7e95..3b6e206 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -2536,6 +2536,7 @@ _copyCommonTableExpr(const CommonTableExpr *from) COPY_STRING_FIELD(ctename); COPY_NODE_FIELD(aliascolnames); + COPY_SCALAR_FIELD(ctematerialized); COPY_NODE_FIELD(ctequery); COPY_LOCATION_FIELD(location); COPY_SCALAR_FIELD(cterecursive); diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c index 5c4fa7d..e7b0fae 100644 --- a/src/backend/nodes/equalfuncs.c +++ b/src/backend/nodes/equalfuncs.c @@ -2791,6 +2791,7 @@ _equalCommonTableExpr(const CommonTableExpr *a, const CommonTableExpr *b) { COMPARE_STRING_FIELD(ctename); COMPARE_NODE_FIELD(aliascolnames); + COMPARE_SCALAR_FIELD(ctematerialized); COMPARE_NODE_FIELD(ctequery); COMPARE_LOCATION_FIELD(location); COMPARE_SCALAR_FIELD(cterecursive); diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 0fde876..b8467cd 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -2980,6 +2980,7 @@ _outCommonTableExpr(StringInfo str, const CommonTableExpr *node) WRITE_STRING_FIELD(ctename); WRITE_NODE_FIELD(aliascolnames); + WRITE_BOOL_FIELD(ctematerialized); WRITE_NODE_FIELD(ctequery); WRITE_LOCATION_FIELD(location); WRITE_BOOL_FIELD(cterecursive); diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c index ec6f256..c653ee3 100644 --- a/src/backend/nodes/readfuncs.c +++ b/src/backend/nodes/readfuncs.c @@ -418,6 +418,7 @@ _readCommonTableExpr(void) READ_STRING_FIELD(ctename); READ_NODE_FIELD(aliascolnames); + READ_BOOL_FIELD(ctematerialized); READ_NODE_FIELD(ctequery); READ_LOCATION_FIELD(location); READ_BOOL_FIELD(cterecursive); diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 4465f00..67f276a 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -645,8 +645,8 @@ subquery_planner(PlannerGlobal *glob, Query *parse, root->partColsUpdated = false; /* - * If there is a WITH list, process each WITH query and build an initplan - * SubPlan structure for it. + * If there is a WITH list, process each WITH query and either convert it + * to RTE_SUBQUERY RTE(s) or build an initplan SubPlan structure for it. */ if (parse->cteList) SS_process_ctes(root); diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index 64272dd..8dd6a20 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -57,6 +57,14 @@ typedef struct finalize_primnode_context Bitmapset *paramids; /* Non-local PARAM_EXEC paramids found */ } finalize_primnode_context; +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; + static Node *build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot, List *plan_params, @@ -75,6 +83,10 @@ static Node *convert_testexpr_mutator(Node *node, static bool subplan_is_hashable(Plan *plan); static bool testexpr_is_hashable(Node *testexpr); static bool hash_ok_operator(OpExpr *expr); +static bool contain_dml(Node *node); +static bool contain_dml_walker(Node *node, void *context); +static void inline_cte(PlannerInfo *root, CommonTableExpr *cte); +static bool inline_cte_walker(Node *node, inline_cte_walker_context *context); static bool simplify_EXISTS_query(PlannerInfo *root, Query *query); static Query *convert_EXISTS_to_ANY(PlannerInfo *root, Query *subselect, Node **testexpr, List **paramIds); @@ -804,10 +816,13 @@ hash_ok_operator(OpExpr *expr) /* * SS_process_ctes: process a query's WITH list * - * We plan each interesting WITH item and convert it to an initplan. + * Consider each CTE in the WITH list and either ignore it (if it's an + * unreferenced SELECT), "inline" it to create a regular sub-SELECT-in-FROM, + * or convert it to an initplan. + * * A side effect is to fill in root->cte_plan_ids with a list that * parallels root->parse->cteList and provides the subplan ID for - * each CTE's initplan. + * each CTE's initplan, or a dummy ID (-1) if we didn't make an initplan. */ void SS_process_ctes(PlannerInfo *root) @@ -839,6 +854,39 @@ SS_process_ctes(PlannerInfo *root) } /* + * Consider inlining the CTE (creating RTE_SUBQUERY RTE(s)) instead of + * implementing it as a separately-planned CTE. + * + * We cannot inline if any of these conditions hold: + * + * 1. The user said not to (the MATERIALIZED option). + * + * 2. The CTE is recursive. + * + * 3. The CTE has side-effects; this includes either not being a plain + * SELECT, or containing volatile functions. Inlining might change + * the side-effects, which is not good. + * + * Otherwise, we always inline. This could be a net loss if the CTE + * is multiply referenced, but not necessarily so: the ability to + * absorb restrictions from the outer query level could outweigh the + * need for duplicate computations. We do not have nearly enough + * information at this point to tell if that's true, so we make the + * user say MATERIALIZED if it's not. + */ + if (!cte->ctematerialized && + !cte->cterecursive && + cmdType == CMD_SELECT && + !contain_dml(cte->ctequery) && + !contain_volatile_functions(cte->ctequery)) + { + inline_cte(root, cte); + /* Make a dummy entry in cte_plan_ids */ + root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1); + continue; + } + + /* * Copy the source Query node. Probably not necessary, but let's keep * this similar to make_subplan. */ @@ -935,6 +983,127 @@ SS_process_ctes(PlannerInfo *root) } /* + * contain_dml: is any subquery not a plain SELECT? + * + * We reject SELECT FOR UPDATE/SHARE as well as INSERT etc. + */ +static bool +contain_dml(Node *node) +{ + return contain_dml_walker(node, NULL); +} + +static bool +contain_dml_walker(Node *node, void *context) +{ + if (node == NULL) + return false; + if (IsA(node, Query)) + { + Query *query = (Query *) node; + + if (query->commandType != CMD_SELECT || + query->rowMarks != NIL) + return true; + + return query_tree_walker(query, contain_dml_walker, context, 0); + } + return expression_tree_walker(node, contain_dml_walker, context); +} + +/* + * inline_cte: convert RTE_CTE references to given CTE into RTE_SUBQUERYs + */ +static void +inline_cte(PlannerInfo *root, CommonTableExpr *cte) +{ + struct inline_cte_walker_context context; + + 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 +inline_cte_walker(Node *node, inline_cte_walker_context *context) +{ + if (node == NULL) + return false; + if (IsA(node, Query)) + { + Query *query = (Query *) node; + + context->levelsup++; + + /* + * Visit the query's RTE nodes after their contents; otherwise + * query_tree_walker would descend into the newly inlined CTE query, + * which we don't want. + */ + (void) query_tree_walker(query, inline_cte_walker, context, + QTW_EXAMINE_RTES_AFTER); + + context->levelsup--; + + return false; + } + else if (IsA(node, RangeTblEntry)) + { + RangeTblEntry *rte = (RangeTblEntry *) node; + + if (rte->rtekind == RTE_CTE && + strcmp(rte->ctename, context->ctename) == 0 && + rte->ctelevelsup == context->levelsup) + { + /* + * Found a reference to replace. Generate a copy of the CTE query + * with appropriate level adjustment for outer references (e.g., + * to other CTEs). + */ + Query *newquery = copyObject(context->ctequery); + + if (context->levelsup > 0) + IncrementVarSublevelsUp((Node *) newquery, context->levelsup, 1); + + /* + * Convert the RTE_CTE RTE into a RTE_SUBQUERY. + * + * Historically, a FOR UPDATE clause has been treated as extending + * into views and subqueries, but not into CTEs. We preserve this + * distinction by not trying to push rowmarks into the new + * subquery. + */ + rte->rtekind = RTE_SUBQUERY; + rte->subquery = newquery; + rte->security_barrier = false; + + /* Zero out CTE-specific fields */ + rte->ctename = NULL; + rte->ctelevelsup = 0; + rte->self_reference = false; + rte->coltypes = NIL; + rte->coltypmods = NIL; + rte->colcollations = NIL; + + /* Count the number of replacements we've done */ + context->refcount--; + } + + return false; + } + + return expression_tree_walker(node, inline_cte_walker, context); +} + + +/* * convert_ANY_sublink_to_join: try to convert an ANY SubLink to a join * * The caller has found an ANY SubLink at the top level of one of the query's diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index c1faf41..5ffdd8f 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -518,7 +518,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); Bit ConstBit BitWithLength BitWithoutLength %type character %type extract_arg -%type opt_varying opt_timezone opt_no_inherit +%type opt_varying opt_timezone opt_no_inherit opt_materialized %type Iconst SignedIconst %type Sconst comment_text notify_payload @@ -11322,17 +11322,23 @@ cte_list: | cte_list ',' common_table_expr { $$ = lappend($1, $3); } ; -common_table_expr: name opt_name_list AS '(' PreparableStmt ')' +common_table_expr: name opt_name_list AS opt_materialized '(' PreparableStmt ')' { CommonTableExpr *n = makeNode(CommonTableExpr); n->ctename = $1; n->aliascolnames = $2; - n->ctequery = $5; + n->ctematerialized = $4; + n->ctequery = $6; n->location = @1; $$ = (Node *) n; } ; +opt_materialized: + MATERIALIZED { $$ = true; } + | /*EMPTY*/ { $$ = false; } + ; + opt_with_clause: with_clause { $$ = $1; } | /*EMPTY*/ { $$ = NULL; } @@ -16214,6 +16220,7 @@ makeRecursiveViewSelect(char *relname, List *aliases, Node *query) /* create common table expression */ cte->ctename = relname; cte->aliascolnames = aliases; + cte->ctematerialized = false; cte->ctequery = query; cte->location = -1; diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 302df16..eb0010d 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -5166,7 +5166,10 @@ get_with_clause(Query *query, deparse_context *context) } appendStringInfoChar(buf, ')'); } - appendStringInfoString(buf, " AS ("); + appendStringInfoString(buf, " AS "); + if (cte->ctematerialized) + appendStringInfoString(buf, "MATERIALIZED "); + appendStringInfoChar(buf, '('); if (PRETTY_INDENT(context)) appendContextKeyword(context, "", 0, 0, 0); get_query_def((Query *) cte->ctequery, buf, context->namespaces, NULL, diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index addc2c2..136f72c 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -1404,6 +1404,7 @@ typedef struct CommonTableExpr NodeTag type; char *ctename; /* query name (never qualified) */ List *aliascolnames; /* optional list of column names */ + bool ctematerialized; /* is this an optimization fence? */ /* SelectStmt/InsertStmt/etc before parse analysis, Query afterwards: */ Node *ctequery; /* the CTE's subquery */ int location; /* token location, or -1 if unknown */ diff --git a/src/test/regress/expected/rowsecurity.out b/src/test/regress/expected/rowsecurity.out index 1d12b01..2e17049 100644 --- a/src/test/regress/expected/rowsecurity.out +++ b/src/test/regress/expected/rowsecurity.out @@ -2179,7 +2179,7 @@ EXPLAIN (COSTS OFF) EXECUTE plancache_test; Filter: (((a % 2) = 0) AND f_leak(b)) (2 rows) -PREPARE plancache_test2 AS WITH q AS (SELECT * FROM z1 WHERE f_leak(b)) SELECT * FROM q,z2; +PREPARE plancache_test2 AS WITH q AS MATERIALIZED (SELECT * FROM z1 WHERE f_leak(b)) SELECT * FROM q,z2; EXPLAIN (COSTS OFF) EXECUTE plancache_test2; QUERY PLAN ------------------------------------------------- @@ -2192,7 +2192,7 @@ EXPLAIN (COSTS OFF) EXECUTE plancache_test2; -> Seq Scan on z2 (7 rows) -PREPARE plancache_test3 AS WITH q AS (SELECT * FROM z2) SELECT * FROM q,z1 WHERE f_leak(z1.b); +PREPARE plancache_test3 AS WITH q AS MATERIALIZED (SELECT * FROM z2) SELECT * FROM q,z1 WHERE f_leak(z1.b); EXPLAIN (COSTS OFF) EXECUTE plancache_test3; QUERY PLAN ----------------------------------------------------- @@ -2826,7 +2826,7 @@ ALTER TABLE t1 ENABLE ROW LEVEL SECURITY; GRANT ALL ON t1 TO regress_rls_bob; INSERT INTO t1 (SELECT x, md5(x::text) FROM generate_series(0,20) x); SET SESSION AUTHORIZATION regress_rls_bob; -WITH cte1 AS (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; +WITH cte1 AS MATERIALIZED (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; NOTICE: f_leak => cfcd208495d565ef66e7dff9f98764da NOTICE: f_leak => c81e728d9d4c2f636f067f89cc14862c NOTICE: f_leak => a87ff679a2f3e71d9181a67b7542122c @@ -2853,7 +2853,8 @@ NOTICE: f_leak => 98f13708210194c475687be6106a3b84 20 | 98f13708210194c475687be6106a3b84 (11 rows) -EXPLAIN (COSTS OFF) WITH cte1 AS (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; +EXPLAIN (COSTS OFF) +WITH cte1 AS MATERIALIZED (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; QUERY PLAN ------------------------------------------------- CTE Scan on cte1 diff --git a/src/test/regress/expected/rowtypes.out b/src/test/regress/expected/rowtypes.out index d6a1a33..14757b4 100644 --- a/src/test/regress/expected/rowtypes.out +++ b/src/test/regress/expected/rowtypes.out @@ -1037,7 +1037,7 @@ from (values (1,row(1,2)), (1,row(null,null)), (1,null), (6 rows) explain (verbose, costs off) -with r(a,b) as +with r(a,b) as materialized (values (1,row(1,2)), (1,row(null,null)), (1,null), (null,row(1,2)), (null,row(null,null)), (null,null) ) select r, r is null as isnull, r is not null as isnotnull from r; @@ -1050,7 +1050,7 @@ select r, r is null as isnull, r is not null as isnotnull from r; Output: "*VALUES*".column1, "*VALUES*".column2 (5 rows) -with r(a,b) as +with r(a,b) as materialized (values (1,row(1,2)), (1,row(null,null)), (1,null), (null,row(1,2)), (null,row(null,null)), (null,null) ) select r, r is null as isnull, r is not null as isnotnull from r; diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index e384cd2..bb10e27 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -3108,7 +3108,7 @@ explain (costs off) INSERT INTO hats VALUES ('h8', 'forbidden') RETURNING *; (5 rows) -- ensure upserting into a rule, with a CTE (different offsets!) works -WITH data(hat_name, hat_color) AS ( +WITH data(hat_name, hat_color) AS MATERIALIZED ( VALUES ('h8', 'green'), ('h9', 'blue'), ('h7', 'forbidden') @@ -3122,7 +3122,8 @@ RETURNING *; h9 | blue (2 rows) -EXPLAIN (costs off) WITH data(hat_name, hat_color) AS ( +EXPLAIN (costs off) +WITH data(hat_name, hat_color) AS MATERIALIZED ( VALUES ('h8', 'green'), ('h9', 'blue'), ('h7', 'forbidden') diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out index 588d069..e2afd6f 100644 --- a/src/test/regress/expected/subselect.out +++ b/src/test/regress/expected/subselect.out @@ -1154,3 +1154,117 @@ fetch backward all in c1; (2 rows) commit; +-- +-- Tests for CTE inlining behavior +-- +-- Basic subquery that can be inlined +explain (verbose, costs off) +with x as (select * from (select f1 from subselect_tbl) ss) +select * from x where f1 = 1; + QUERY PLAN +---------------------------------- + Seq Scan on public.subselect_tbl + Output: subselect_tbl.f1 + Filter: (subselect_tbl.f1 = 1) +(3 rows) + +-- Explicitly request materialization +explain (verbose, costs off) +with x as materialized (select * from (select f1 from subselect_tbl) ss) +select * from x where f1 = 1; + QUERY PLAN +------------------------------------------ + CTE Scan on x + Output: x.f1 + Filter: (x.f1 = 1) + CTE x + -> Seq Scan on public.subselect_tbl + Output: subselect_tbl.f1 +(6 rows) + +-- Stable functions are safe to inline +explain (verbose, costs off) +with x as (select * from (select f1, now() from subselect_tbl) ss) +select * from x where f1 = 1; + QUERY PLAN +----------------------------------- + Seq Scan on public.subselect_tbl + Output: subselect_tbl.f1, now() + Filter: (subselect_tbl.f1 = 1) +(3 rows) + +-- Volatile functions prevent inlining +explain (verbose, costs off) +with x as (select * from (select f1, random() from subselect_tbl) ss) +select * from x where f1 = 1; + QUERY PLAN +---------------------------------------------- + CTE Scan on x + Output: x.f1, x.random + Filter: (x.f1 = 1) + CTE x + -> Seq Scan on public.subselect_tbl + Output: subselect_tbl.f1, random() +(6 rows) + +-- SELECT FOR UPDATE cannot be inlined +explain (verbose, costs off) +with x as (select * from (select f1 from subselect_tbl for update) ss) +select * from x where f1 = 1; + QUERY PLAN +-------------------------------------------------------------------- + CTE Scan on x + Output: x.f1 + Filter: (x.f1 = 1) + CTE x + -> Subquery Scan on ss + Output: ss.f1 + -> LockRows + Output: subselect_tbl.f1, subselect_tbl.ctid + -> Seq Scan on public.subselect_tbl + Output: subselect_tbl.f1, subselect_tbl.ctid +(10 rows) + +-- Check handling of outer references +explain (verbose, costs off) +with x as (select * from int4_tbl) +select * from (with y as (select * from x) select * from y) ss; + QUERY PLAN +----------------------------- + Seq Scan on public.int4_tbl + Output: int4_tbl.f1 +(2 rows) + +explain (verbose, costs off) +with x as materialized (select * from int4_tbl) +select * from (with y as (select * from x) select * from y) ss; + QUERY PLAN +------------------------------------- + CTE Scan on x + Output: x.f1 + CTE x + -> Seq Scan on public.int4_tbl + Output: int4_tbl.f1 +(5 rows) + +-- Ensure that we inline the currect CTE when there are +-- multiple CTEs with the same name +explain (verbose, costs off) +with x as (select 1 as y) +select * from (with x as (select 2 as y) select * from x) ss; + QUERY PLAN +------------- + Result + Output: 2 +(2 rows) + +-- Row marks are not pushed into CTEs +explain (verbose, costs off) +with x as (select * from subselect_tbl) +select * from x for update; + QUERY PLAN +---------------------------------------------------------------- + Seq Scan on public.subselect_tbl + Output: subselect_tbl.f1, subselect_tbl.f2, subselect_tbl.f3 +(2 rows) + diff --git a/src/test/regress/sql/rowsecurity.sql b/src/test/regress/sql/rowsecurity.sql index 38e9b38..52da276 100644 --- a/src/test/regress/sql/rowsecurity.sql +++ b/src/test/regress/sql/rowsecurity.sql @@ -840,10 +840,10 @@ EXPLAIN (COSTS OFF) SELECT * FROM z1 WHERE f_leak(b); PREPARE plancache_test AS SELECT * FROM z1 WHERE f_leak(b); EXPLAIN (COSTS OFF) EXECUTE plancache_test; -PREPARE plancache_test2 AS WITH q AS (SELECT * FROM z1 WHERE f_leak(b)) SELECT * FROM q,z2; +PREPARE plancache_test2 AS WITH q AS MATERIALIZED (SELECT * FROM z1 WHERE f_leak(b)) SELECT * FROM q,z2; EXPLAIN (COSTS OFF) EXECUTE plancache_test2; -PREPARE plancache_test3 AS WITH q AS (SELECT * FROM z2) SELECT * FROM q,z1 WHERE f_leak(z1.b); +PREPARE plancache_test3 AS WITH q AS MATERIALIZED (SELECT * FROM z2) SELECT * FROM q,z1 WHERE f_leak(z1.b); EXPLAIN (COSTS OFF) EXECUTE plancache_test3; SET ROLE regress_rls_group1; @@ -1071,8 +1071,9 @@ INSERT INTO t1 (SELECT x, md5(x::text) FROM generate_series(0,20) x); SET SESSION AUTHORIZATION regress_rls_bob; -WITH cte1 AS (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; -EXPLAIN (COSTS OFF) WITH cte1 AS (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; +WITH cte1 AS MATERIALIZED (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; +EXPLAIN (COSTS OFF) +WITH cte1 AS MATERIALIZED (SELECT * FROM t1 WHERE f_leak(b)) SELECT * FROM cte1; WITH cte1 AS (UPDATE t1 SET a = a + 1 RETURNING *) SELECT * FROM cte1; --fail WITH cte1 AS (UPDATE t1 SET a = a RETURNING *) SELECT * FROM cte1; --ok diff --git a/src/test/regress/sql/rowtypes.sql b/src/test/regress/sql/rowtypes.sql index e6d3898..b3b0774 100644 --- a/src/test/regress/sql/rowtypes.sql +++ b/src/test/regress/sql/rowtypes.sql @@ -428,12 +428,12 @@ from (values (1,row(1,2)), (1,row(null,null)), (1,null), (null,row(1,2)), (null,row(null,null)), (null,null) ) r(a,b); explain (verbose, costs off) -with r(a,b) as +with r(a,b) as materialized (values (1,row(1,2)), (1,row(null,null)), (1,null), (null,row(1,2)), (null,row(null,null)), (null,null) ) select r, r is null as isnull, r is not null as isnotnull from r; -with r(a,b) as +with r(a,b) as materialized (values (1,row(1,2)), (1,row(null,null)), (1,null), (null,row(1,2)), (null,row(null,null)), (null,null) ) select r, r is null as isnull, r is not null as isnotnull from r; diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql index f4ee30e..6666951 100644 --- a/src/test/regress/sql/rules.sql +++ b/src/test/regress/sql/rules.sql @@ -1132,7 +1132,7 @@ SELECT tablename, rulename, definition FROM pg_rules explain (costs off) INSERT INTO hats VALUES ('h8', 'forbidden') RETURNING *; -- ensure upserting into a rule, with a CTE (different offsets!) works -WITH data(hat_name, hat_color) AS ( +WITH data(hat_name, hat_color) AS MATERIALIZED ( VALUES ('h8', 'green'), ('h9', 'blue'), ('h7', 'forbidden') @@ -1140,7 +1140,8 @@ WITH data(hat_name, hat_color) AS ( INSERT INTO hats SELECT * FROM data RETURNING *; -EXPLAIN (costs off) WITH data(hat_name, hat_color) AS ( +EXPLAIN (costs off) +WITH data(hat_name, hat_color) AS MATERIALIZED ( VALUES ('h8', 'green'), ('h9', 'blue'), ('h7', 'forbidden') diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql index 843f511..3dba35e 100644 --- a/src/test/regress/sql/subselect.sql +++ b/src/test/regress/sql/subselect.sql @@ -625,3 +625,52 @@ move forward all in c1; fetch backward all in c1; commit; + +-- +-- Tests for CTE inlining behavior +-- + +-- Basic subquery that can be inlined +explain (verbose, costs off) +with x as (select * from (select f1 from subselect_tbl) ss) +select * from x where f1 = 1; + +-- Explicitly request materialization +explain (verbose, costs off) +with x as materialized (select * from (select f1 from subselect_tbl) ss) +select * from x where f1 = 1; + +-- Stable functions are safe to inline +explain (verbose, costs off) +with x as (select * from (select f1, now() from subselect_tbl) ss) +select * from x where f1 = 1; + +-- Volatile functions prevent inlining +explain (verbose, costs off) +with x as (select * from (select f1, random() from subselect_tbl) ss) +select * from x where f1 = 1; + +-- SELECT FOR UPDATE cannot be inlined +explain (verbose, costs off) +with x as (select * from (select f1 from subselect_tbl for update) ss) +select * from x where f1 = 1; + +-- Check handling of outer references +explain (verbose, costs off) +with x as (select * from int4_tbl) +select * from (with y as (select * from x) select * from y) ss; + +explain (verbose, costs off) +with x as materialized (select * from int4_tbl) +select * from (with y as (select * from x) select * from y) ss; + +-- Ensure that we inline the currect CTE when there are +-- multiple CTEs with the same name +explain (verbose, costs off) +with x as (select 1 as y) +select * from (with x as (select 2 as y) select * from x) ss; + +-- Row marks are not pushed into CTEs +explain (verbose, costs off) +with x as (select * from subselect_tbl) +select * from x for update;