diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c index 123b4eb6bf..41fbeec8fd 100644 --- a/src/backend/utils/adt/int8.c +++ b/src/backend/utils/adt/int8.c @@ -833,6 +833,21 @@ int8inc_support(PG_FUNCTION_ARGS) SupportRequestWFuncMonotonic *req = (SupportRequestWFuncMonotonic *) rawreq; MonotonicFunction monotonic = MONOTONICFUNC_NONE; int frameOptions = req->window_clause->frameOptions; + WindowFunc *wfunc = req->window_func; + + if (list_length(wfunc->args) == 1) + { + Node *expr = eval_const_expressions(NULL, linitial(wfunc->args)); + + /* + * Due to the Node representation of WindowClause runConditions in + * version prior to v17, we need to insist that the count arg is + * Const to allow safe application of the runCondition + * optimization. + */ + if (!IsA(expr, Const)) + PG_RETURN_POINTER(NULL); + } /* No ORDER BY clause then all rows are peers */ if (req->window_clause->orderClause == NIL) diff --git a/src/backend/utils/adt/windowfuncs.c b/src/backend/utils/adt/windowfuncs.c index b87a624fb2..0c7cc55845 100644 --- a/src/backend/utils/adt/windowfuncs.c +++ b/src/backend/utils/adt/windowfuncs.c @@ -14,6 +14,7 @@ #include "postgres.h" #include "nodes/supportnodes.h" +#include "optimizer/optimizer.h" #include "utils/builtins.h" #include "windowapi.h" @@ -486,13 +487,29 @@ window_ntile_support(PG_FUNCTION_ARGS) if (IsA(rawreq, SupportRequestWFuncMonotonic)) { SupportRequestWFuncMonotonic *req = (SupportRequestWFuncMonotonic *) rawreq; + WindowFunc *wfunc = req->window_func; - /* - * ntile() is monotonically increasing as the number of buckets cannot - * change after the first call - */ - req->monotonic = MONOTONICFUNC_INCREASING; - PG_RETURN_POINTER(req); + if (list_length(wfunc->args) == 1) + { + Node *expr = eval_const_expressions(NULL, linitial(wfunc->args)); + + /* + * Due to the Node representation of WindowClause runConditions in + * version prior to v17, we need to insist that ntile arg is Const + * to allow safe application of the runCondition optimization. + */ + if (IsA(expr, Const)) + { + /* + * ntile() is monotonically increasing as the number of + * buckets cannot change after the first call + */ + req->monotonic = MONOTONICFUNC_INCREASING; + PG_RETURN_POINTER(req); + } + } + + PG_RETURN_POINTER(NULL); } if (IsA(rawreq, SupportRequestOptimizeWindowClause)) diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out index 8612788702..1a9cc66a6b 100644 --- a/src/test/regress/expected/window.out +++ b/src/test/regress/expected/window.out @@ -3577,13 +3577,13 @@ EXPLAIN (COSTS OFF) SELECT * FROM (SELECT empno, salary, - count(empno) OVER (ORDER BY salary DESC) c + count(1) OVER (ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; - QUERY PLAN ---------------------------------------------------------- + QUERY PLAN +------------------------------------------- WindowAgg - Run Condition: (count(empsalary.empno) OVER (?) <= 3) + Run Condition: (count(1) OVER (?) <= 3) -> Sort Sort Key: empsalary.salary DESC -> Seq Scan on empsalary @@ -3592,7 +3592,7 @@ WHERE c <= 3; SELECT * FROM (SELECT empno, salary, - count(empno) OVER (ORDER BY salary DESC) c + count(1) OVER (ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; empno | salary | c @@ -3704,19 +3704,19 @@ WHERE rn < 3; -> Seq Scan on empsalary (6 rows) --- likewise with count(empno) instead of row_number() +-- likewise with count(1) instead of row_number() EXPLAIN (COSTS OFF) SELECT * FROM (SELECT empno, depname, salary, - count(empno) OVER (PARTITION BY depname ORDER BY salary DESC) c + count(1) OVER (PARTITION BY depname ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; QUERY PLAN ------------------------------------------------------------ WindowAgg - Run Condition: (count(empsalary.empno) OVER (?) <= 3) + Run Condition: (count(1) OVER (?) <= 3) -> Sort Sort Key: empsalary.depname, empsalary.salary DESC -> Seq Scan on empsalary @@ -3727,7 +3727,7 @@ SELECT * FROM (SELECT empno, depname, salary, - count(empno) OVER (PARTITION BY depname ORDER BY salary DESC) c + count(1) OVER (PARTITION BY depname ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; empno | depname | salary | c @@ -3749,13 +3749,13 @@ SELECT * FROM (SELECT empno, depname, salary, - count(empno) OVER () c + count(1) OVER () c FROM empsalary) emp WHERE c = 1; - QUERY PLAN --------------------------------------------------------- + QUERY PLAN +------------------------------------------ WindowAgg - Run Condition: (count(empsalary.empno) OVER (?) = 1) + Run Condition: (count(1) OVER (?) = 1) -> Seq Scan on empsalary (3 rows) @@ -3763,7 +3763,7 @@ WHERE c = 1; EXPLAIN (COSTS OFF) SELECT * FROM (SELECT *, - count(salary) OVER (PARTITION BY depname || '') c1, -- w1 + count(1) OVER (PARTITION BY depname || '') c1, -- w1 row_number() OVER (PARTITION BY depname) rn, -- w2 count(*) OVER (PARTITION BY depname) c2, -- w2 count(*) OVER (PARTITION BY '' || depname) c3, -- w3 @@ -3775,7 +3775,7 @@ SELECT * FROM Subquery Scan on e -> WindowAgg Filter: (((row_number() OVER (?)) <= 1) AND ((ntile(2) OVER (?)) < 2)) - Run Condition: (count(empsalary.salary) OVER (?) <= 3) + Run Condition: (count(1) OVER (?) <= 3) -> Sort Sort Key: (((empsalary.depname)::text || ''::text)) -> WindowAgg @@ -3791,7 +3791,7 @@ SELECT * FROM -- Ensure we correctly filter out all of the run conditions from each window SELECT * FROM (SELECT *, - count(salary) OVER (PARTITION BY depname || '') c1, -- w1 + count(1) OVER (PARTITION BY depname || '') c1, -- w1 row_number() OVER (PARTITION BY depname) rn, -- w2 count(*) OVER (PARTITION BY depname) c2, -- w2 count(*) OVER (PARTITION BY '' || depname) c3, -- w3 @@ -3804,32 +3804,6 @@ SELECT * FROM sales | 3 | 4800 | 08-01-2007 | 3 | 1 | 3 | 3 | 1 (2 rows) --- Ensure we remove references to reduced outer joins as nulling rels in run --- conditions -EXPLAIN (COSTS OFF) -SELECT 1 FROM - (SELECT ntile(e2.salary) OVER (PARTITION BY e1.depname) AS c - FROM empsalary e1 LEFT JOIN empsalary e2 ON TRUE - WHERE e1.empno = e2.empno) s -WHERE s.c = 1; - QUERY PLAN ---------------------------------------------------------- - Subquery Scan on s - Filter: (s.c = 1) - -> WindowAgg - Run Condition: (ntile(e2.salary) OVER (?) <= 1) - -> Sort - Sort Key: e1.depname - -> Merge Join - Merge Cond: (e1.empno = e2.empno) - -> Sort - Sort Key: e1.empno - -> Seq Scan on empsalary e1 - -> Sort - Sort Key: e2.empno - -> Seq Scan on empsalary e2 -(14 rows) - -- Tests to ensure we don't push down the run condition when it's not valid to -- do so. -- Ensure we don't push down when the frame options show that the window @@ -3889,6 +3863,42 @@ WHERE c = 1; -> Seq Scan on empsalary (6 rows) +-- Ensure we don't use a run condition when the WindowFunc arg contains a Var +EXPLAIN (COSTS OFF) +SELECT * FROM + (SELECT empno, + salary, + count(empno) OVER (ORDER BY empno DESC) c + FROM empsalary) emp +WHERE c = 1; + QUERY PLAN +---------------------------------------------- + Subquery Scan on emp + Filter: (emp.c = 1) + -> WindowAgg + -> Sort + Sort Key: empsalary.empno DESC + -> Seq Scan on empsalary +(6 rows) + +-- As above but with ntile(). +EXPLAIN (COSTS OFF) +SELECT * FROM + (SELECT empno, + salary, + ntile(empno::int) OVER (ORDER BY empno DESC) nt + FROM empsalary) emp +WHERE nt = 1; + QUERY PLAN +---------------------------------------------- + Subquery Scan on emp + Filter: (emp.nt = 1) + -> WindowAgg + -> Sort + Sort Key: empsalary.empno DESC + -> Seq Scan on empsalary +(6 rows) + -- Ensure we don't use a run condition when the WindowFunc contains subplans EXPLAIN (COSTS OFF) SELECT * FROM diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql index c0ad51ca54..e35c16a827 100644 --- a/src/test/regress/sql/window.sql +++ b/src/test/regress/sql/window.sql @@ -1120,14 +1120,14 @@ EXPLAIN (COSTS OFF) SELECT * FROM (SELECT empno, salary, - count(empno) OVER (ORDER BY salary DESC) c + count(1) OVER (ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; SELECT * FROM (SELECT empno, salary, - count(empno) OVER (ORDER BY salary DESC) c + count(1) OVER (ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; @@ -1183,13 +1183,13 @@ SELECT empno, depname FROM FROM empsalary) emp WHERE rn < 3; --- likewise with count(empno) instead of row_number() +-- likewise with count(1) instead of row_number() EXPLAIN (COSTS OFF) SELECT * FROM (SELECT empno, depname, salary, - count(empno) OVER (PARTITION BY depname ORDER BY salary DESC) c + count(1) OVER (PARTITION BY depname ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; @@ -1198,7 +1198,7 @@ SELECT * FROM (SELECT empno, depname, salary, - count(empno) OVER (PARTITION BY depname ORDER BY salary DESC) c + count(1) OVER (PARTITION BY depname ORDER BY salary DESC) c FROM empsalary) emp WHERE c <= 3; @@ -1209,7 +1209,7 @@ SELECT * FROM (SELECT empno, depname, salary, - count(empno) OVER () c + count(1) OVER () c FROM empsalary) emp WHERE c = 1; @@ -1217,7 +1217,7 @@ WHERE c = 1; EXPLAIN (COSTS OFF) SELECT * FROM (SELECT *, - count(salary) OVER (PARTITION BY depname || '') c1, -- w1 + count(1) OVER (PARTITION BY depname || '') c1, -- w1 row_number() OVER (PARTITION BY depname) rn, -- w2 count(*) OVER (PARTITION BY depname) c2, -- w2 count(*) OVER (PARTITION BY '' || depname) c3, -- w3 @@ -1228,7 +1228,7 @@ SELECT * FROM -- Ensure we correctly filter out all of the run conditions from each window SELECT * FROM (SELECT *, - count(salary) OVER (PARTITION BY depname || '') c1, -- w1 + count(1) OVER (PARTITION BY depname || '') c1, -- w1 row_number() OVER (PARTITION BY depname) rn, -- w2 count(*) OVER (PARTITION BY depname) c2, -- w2 count(*) OVER (PARTITION BY '' || depname) c3, -- w3 @@ -1236,15 +1236,6 @@ SELECT * FROM FROM empsalary ) e WHERE rn <= 1 AND c1 <= 3 AND nt < 2; --- Ensure we remove references to reduced outer joins as nulling rels in run --- conditions -EXPLAIN (COSTS OFF) -SELECT 1 FROM - (SELECT ntile(e2.salary) OVER (PARTITION BY e1.depname) AS c - FROM empsalary e1 LEFT JOIN empsalary e2 ON TRUE - WHERE e1.empno = e2.empno) s -WHERE s.c = 1; - -- Tests to ensure we don't push down the run condition when it's not valid to -- do so. @@ -1278,6 +1269,24 @@ SELECT * FROM FROM empsalary) emp WHERE c = 1; +-- Ensure we don't use a run condition when the WindowFunc arg contains a Var +EXPLAIN (COSTS OFF) +SELECT * FROM + (SELECT empno, + salary, + count(empno) OVER (ORDER BY empno DESC) c + FROM empsalary) emp +WHERE c = 1; + +-- As above but with ntile(). +EXPLAIN (COSTS OFF) +SELECT * FROM + (SELECT empno, + salary, + ntile(empno::int) OVER (ORDER BY empno DESC) nt + FROM empsalary) emp +WHERE nt = 1; + -- Ensure we don't use a run condition when the WindowFunc contains subplans EXPLAIN (COSTS OFF) SELECT * FROM