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Postgres FD Implementation
Commit e9f2703a authored by Tom Lane's avatar Tom Lane
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Fix postgres_fdw to cope with duplicate GROUP BY entries. 

Commit 7012b132, which added the ability to push down aggregates and
grouping to the remote server, wasn't careful to ensure that the remote
server would have the same idea we do about which columns are the grouping
columns, in cases where there are textually identical GROUP BY expressions.
Such cases typically led to "targetlist item has multiple sortgroupref
labels" errors.

To fix this reliably, switch over to using "GROUP BY column-number" syntax
rather than "GROUP BY expression" in transmitted queries, and adjust
foreign_grouping_ok() to be more careful about duplicating the sortgroupref
labeling of the local pathtarget.

Per bug #14890 from Sean Johnston.  Back-patch to v10 where the buggy code
was introduced.

Jeevan Chalke, reviewed by Ashutosh Bapat

Discussion: https://postgr.es/m/20171107134948.1508.94783@wrigleys.postgresql.org
parent 680d5405
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Showing with 150 additions and 119 deletions
contrib/postgres_fdw/deparse.c
View file @ e9f2703a
......@@ -178,7 +178,7 @@ static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
static void appendAggOrderBy(List *orderList, List *targetList,
deparse_expr_cxt *context);
static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
static Node *deparseSortGroupClause(Index ref, List *tlist,
static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
deparse_expr_cxt *context);
/*
......@@ -2853,7 +2853,7 @@ appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
first = false;
sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
context);
false, context);
sortcoltype = exprType(sortexpr);
/* See whether operator is default < or > for datatype */
typentry = lookup_type_cache(sortcoltype,
......@@ -2960,7 +2960,7 @@ appendGroupByClause(List *tlist, deparse_expr_cxt *context)
appendStringInfoString(buf, ", ");
first = false;
deparseSortGroupClause(grp->tleSortGroupRef, tlist, context);
deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
}
}
......@@ -3047,7 +3047,8 @@ appendFunctionName(Oid funcid, deparse_expr_cxt *context)
* need not find it again.
*/
static Node *
deparseSortGroupClause(Index ref, List *tlist, deparse_expr_cxt *context)
deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
deparse_expr_cxt *context)
{
StringInfo buf = context->buf;
TargetEntry *tle;
......@@ -3056,7 +3057,13 @@ deparseSortGroupClause(Index ref, List *tlist, deparse_expr_cxt *context)
tle = get_sortgroupref_tle(ref, tlist);
expr = tle->expr;
if (expr && IsA(expr, Const))
if (force_colno)
{
/* Use column-number form when requested by caller. */
Assert(!tle->resjunk);
appendStringInfo(buf, "%d", tle->resno);
}
else if (expr && IsA(expr, Const))
{
/*
* Force a typecast here so that we don't emit something like "GROUP
......
contrib/postgres_fdw/expected/postgres_fdw.out
View file @ e9f2703a
......@@ -2462,8 +2462,8 @@ DROP ROLE regress_view_owner;
-- Simple aggregates
explain (verbose, costs off)
select count(c6), sum(c1), avg(c1), min(c2), max(c1), stddev(c2), sum(c1) * (random() <= 1)::int as sum2 from ft1 where c2 < 5 group by c2 order by 1, 2;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------
Result
Output: (count(c6)), (sum(c1)), (avg(c1)), (min(c2)), (max(c1)), (stddev(c2)), ((sum(c1)) * ((random() <= '1'::double precision))::integer), c2
-> Sort
......@@ -2472,7 +2472,7 @@ select count(c6), sum(c1), avg(c1), min(c2), max(c1), stddev(c2), sum(c1) * (ran
-> Foreign Scan
Output: (count(c6)), (sum(c1)), (avg(c1)), (min(c2)), (max(c1)), (stddev(c2)), c2
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT count(c6), sum("C 1"), avg("C 1"), min(c2), max("C 1"), stddev(c2), c2 FROM "S 1"."T 1" WHERE ((c2 < 5)) GROUP BY c2
Remote SQL: SELECT count(c6), sum("C 1"), avg("C 1"), min(c2), max("C 1"), stddev(c2), c2 FROM "S 1"."T 1" WHERE ((c2 < 5)) GROUP BY 7
(9 rows)
select count(c6), sum(c1), avg(c1), min(c2), max(c1), stddev(c2), sum(c1) * (random() <= 1)::int as sum2 from ft1 where c2 < 5 group by c2 order by 1, 2;
......@@ -2531,15 +2531,15 @@ select sum(t1.c1), count(t2.c1) from ft1 t1 inner join ft2 t2 on (t1.c1 = t2.c1)
-- GROUP BY clause having expressions
explain (verbose, costs off)
select c2/2, sum(c2) * (c2/2) from ft1 group by c2/2 order by c2/2;
QUERY PLAN
------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------
Sort
Output: ((c2 / 2)), ((sum(c2) * (c2 / 2)))
Sort Key: ((ft1.c2 / 2))
-> Foreign Scan
Output: ((c2 / 2)), ((sum(c2) * (c2 / 2)))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT (c2 / 2), (sum(c2) * (c2 / 2)) FROM "S 1"."T 1" GROUP BY ((c2 / 2))
Remote SQL: SELECT (c2 / 2), (sum(c2) * (c2 / 2)) FROM "S 1"."T 1" GROUP BY 1
(7 rows)
select c2/2, sum(c2) * (c2/2) from ft1 group by c2/2 order by c2/2;
......@@ -2555,8 +2555,8 @@ select c2/2, sum(c2) * (c2/2) from ft1 group by c2/2 order by c2/2;
-- Aggregates in subquery are pushed down.
explain (verbose, costs off)
select count(x.a), sum(x.a) from (select c2 a, sum(c1) b from ft1 group by c2, sqrt(c1) order by 1, 2) x;
QUERY PLAN
----------------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------
Aggregate
Output: count(ft1.c2), sum(ft1.c2)
-> Sort
......@@ -2565,7 +2565,7 @@ select count(x.a), sum(x.a) from (select c2 a, sum(c1) b from ft1 group by c2, s
-> Foreign Scan
Output: ft1.c2, (sum(ft1.c1)), (sqrt((ft1.c1)::double precision))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, sum("C 1"), sqrt("C 1") FROM "S 1"."T 1" GROUP BY c2, (sqrt("C 1"))
Remote SQL: SELECT c2, sum("C 1"), sqrt("C 1") FROM "S 1"."T 1" GROUP BY 1, 3
(9 rows)
select count(x.a), sum(x.a) from (select c2 a, sum(c1) b from ft1 group by c2, sqrt(c1) order by 1, 2) x;
......@@ -2585,7 +2585,7 @@ select c2 * (random() <= 1)::int as sum1, sum(c1) * c2 as sum2 from ft1 group by
-> Foreign Scan
Output: (c2 * ((random() <= '1'::double precision))::integer), ((sum(c1) * c2)), c2
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT (sum("C 1") * c2), c2 FROM "S 1"."T 1" GROUP BY c2
Remote SQL: SELECT (sum("C 1") * c2), c2 FROM "S 1"."T 1" GROUP BY 2
(7 rows)
select c2 * (random() <= 1)::int as sum1, sum(c1) * c2 as sum2 from ft1 group by c2 order by 1, 2;
......@@ -2622,15 +2622,15 @@ select c2 * (random() <= 1)::int as c2 from ft2 group by c2 * (random() <= 1)::i
-- GROUP BY clause in various forms, cardinal, alias and constant expression
explain (verbose, costs off)
select count(c2) w, c2 x, 5 y, 7.0 z from ft1 group by 2, y, 9.0::int order by 2;
QUERY PLAN
----------------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------
Sort
Output: (count(c2)), c2, 5, 7.0, 9
Sort Key: ft1.c2
-> Foreign Scan
Output: (count(c2)), c2, 5, 7.0, 9
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT count(c2), c2, 5, 7.0, 9 FROM "S 1"."T 1" GROUP BY c2, 5::integer, 9::integer
Remote SQL: SELECT count(c2), c2, 5, 7.0, 9 FROM "S 1"."T 1" GROUP BY 2, 3, 5
(7 rows)
select count(c2) w, c2 x, 5 y, 7.0 z from ft1 group by 2, y, 9.0::int order by 2;
......@@ -2648,18 +2648,41 @@ select count(c2) w, c2 x, 5 y, 7.0 z from ft1 group by 2, y, 9.0::int order by 2
100 | 9 | 5 | 7.0
(10 rows)
-- GROUP BY clause referring to same column multiple times
-- Also, ORDER BY contains an aggregate function
explain (verbose, costs off)
select c2, c2 from ft1 where c2 > 6 group by 1, 2 order by sum(c1);
QUERY PLAN
-----------------------------------------------------------------------------------------------
Sort
Output: c2, c2, (sum(c1))
Sort Key: (sum(ft1.c1))
-> Foreign Scan
Output: c2, c2, (sum(c1))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, c2, sum("C 1") FROM "S 1"."T 1" WHERE ((c2 > 6)) GROUP BY 1, 2
(7 rows)
select c2, c2 from ft1 where c2 > 6 group by 1, 2 order by sum(c1);
c2 | c2
----+----
7 | 7
8 | 8
9 | 9
(3 rows)
-- Testing HAVING clause shippability
explain (verbose, costs off)
select c2, sum(c1) from ft2 group by c2 having avg(c1) < 500 and sum(c1) < 49800 order by c2;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------
Sort
Output: c2, (sum(c1))
Sort Key: ft2.c2
-> Foreign Scan
Output: c2, (sum(c1))
Relations: Aggregate on (public.ft2)
Remote SQL: SELECT c2, sum("C 1") FROM "S 1"."T 1" GROUP BY c2 HAVING ((avg("C 1") < 500::numeric)) AND ((sum("C 1") < 49800))
Remote SQL: SELECT c2, sum("C 1") FROM "S 1"."T 1" GROUP BY 1 HAVING ((avg("C 1") < 500::numeric)) AND ((sum("C 1") < 49800))
(7 rows)
select c2, sum(c1) from ft2 group by c2 having avg(c1) < 500 and sum(c1) < 49800 order by c2;
......@@ -2672,15 +2695,15 @@ select c2, sum(c1) from ft2 group by c2 having avg(c1) < 500 and sum(c1) < 49800
-- Unshippable HAVING clause will be evaluated locally, and other qual in HAVING clause is pushed down
explain (verbose, costs off)
select count(*) from (select c5, count(c1) from ft1 group by c5, sqrt(c2) having (avg(c1) / avg(c1)) * random() <= 1 and avg(c1) < 500) x;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------
Aggregate
Output: count(*)
-> Foreign Scan
Output: ft1.c5, NULL::bigint, (sqrt((ft1.c2)::double precision))
Filter: (((((avg(ft1.c1)) / (avg(ft1.c1))))::double precision * random()) <= '1'::double precision)
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c5, NULL::bigint, sqrt(c2), avg("C 1") FROM "S 1"."T 1" GROUP BY c5, (sqrt(c2)) HAVING ((avg("C 1") < 500::numeric))
Remote SQL: SELECT c5, NULL::bigint, sqrt(c2), avg("C 1") FROM "S 1"."T 1" GROUP BY 1, 3 HAVING ((avg("C 1") < 500::numeric))
(7 rows)
select count(*) from (select c5, count(c1) from ft1 group by c5, sqrt(c2) having (avg(c1) / avg(c1)) * random() <= 1 and avg(c1) < 500) x;
......@@ -2710,15 +2733,15 @@ select sum(c1) from ft1 group by c2 having avg(c1 * (random() <= 1)::int) > 100
-- ORDER BY within aggregate, same column used to order
explain (verbose, costs off)
select array_agg(c1 order by c1) from ft1 where c1 < 100 group by c2 order by 1;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------
Sort
Output: (array_agg(c1 ORDER BY c1)), c2
Sort Key: (array_agg(ft1.c1 ORDER BY ft1.c1))
-> Foreign Scan
Output: (array_agg(c1 ORDER BY c1)), c2
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT array_agg("C 1" ORDER BY "C 1" ASC NULLS LAST), c2 FROM "S 1"."T 1" WHERE (("C 1" < 100)) GROUP BY c2
Remote SQL: SELECT array_agg("C 1" ORDER BY "C 1" ASC NULLS LAST), c2 FROM "S 1"."T 1" WHERE (("C 1" < 100)) GROUP BY 2
(7 rows)
select array_agg(c1 order by c1) from ft1 where c1 < 100 group by c2 order by 1;
......@@ -2756,15 +2779,15 @@ select array_agg(c5 order by c1 desc) from ft2 where c2 = 6 and c1 < 50;
-- DISTINCT within aggregate
explain (verbose, costs off)
select array_agg(distinct (t1.c1)%5) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) where t1.c1 < 20 or (t1.c1 is null and t2.c1 < 5) group by (t2.c1)%3 order by 1;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sort
Output: (array_agg(DISTINCT (t1.c1 % 5))), ((t2.c1 % 3))
Sort Key: (array_agg(DISTINCT (t1.c1 % 5)))
-> Foreign Scan
Output: (array_agg(DISTINCT (t1.c1 % 5))), ((t2.c1 % 3))
Relations: Aggregate on ((public.ft4 t1) FULL JOIN (public.ft5 t2))
Remote SQL: SELECT array_agg(DISTINCT (r1.c1 % 5)), (r2.c1 % 3) FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) WHERE (((r1.c1 < 20) OR ((r1.c1 IS NULL) AND (r2.c1 < 5)))) GROUP BY ((r2.c1 % 3))
Remote SQL: SELECT array_agg(DISTINCT (r1.c1 % 5)), (r2.c1 % 3) FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) WHERE (((r1.c1 < 20) OR ((r1.c1 IS NULL) AND (r2.c1 < 5)))) GROUP BY 2
(7 rows)
select array_agg(distinct (t1.c1)%5) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) where t1.c1 < 20 or (t1.c1 is null and t2.c1 < 5) group by (t2.c1)%3 order by 1;
......@@ -2777,15 +2800,15 @@ select array_agg(distinct (t1.c1)%5) from ft4 t1 full join ft5 t2 on (t1.c1 = t2
-- DISTINCT combined with ORDER BY within aggregate
explain (verbose, costs off)
select array_agg(distinct (t1.c1)%5 order by (t1.c1)%5) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) where t1.c1 < 20 or (t1.c1 is null and t2.c1 < 5) group by (t2.c1)%3 order by 1;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sort
Output: (array_agg(DISTINCT (t1.c1 % 5) ORDER BY (t1.c1 % 5))), ((t2.c1 % 3))
Sort Key: (array_agg(DISTINCT (t1.c1 % 5) ORDER BY (t1.c1 % 5)))
-> Foreign Scan
Output: (array_agg(DISTINCT (t1.c1 % 5) ORDER BY (t1.c1 % 5))), ((t2.c1 % 3))
Relations: Aggregate on ((public.ft4 t1) FULL JOIN (public.ft5 t2))
Remote SQL: SELECT array_agg(DISTINCT (r1.c1 % 5) ORDER BY ((r1.c1 % 5)) ASC NULLS LAST), (r2.c1 % 3) FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) WHERE (((r1.c1 < 20) OR ((r1.c1 IS NULL) AND (r2.c1 < 5)))) GROUP BY ((r2.c1 % 3))
Remote SQL: SELECT array_agg(DISTINCT (r1.c1 % 5) ORDER BY ((r1.c1 % 5)) ASC NULLS LAST), (r2.c1 % 3) FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) WHERE (((r1.c1 < 20) OR ((r1.c1 IS NULL) AND (r2.c1 < 5)))) GROUP BY 2
(7 rows)
select array_agg(distinct (t1.c1)%5 order by (t1.c1)%5) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) where t1.c1 < 20 or (t1.c1 is null and t2.c1 < 5) group by (t2.c1)%3 order by 1;
......@@ -2797,15 +2820,15 @@ select array_agg(distinct (t1.c1)%5 order by (t1.c1)%5) from ft4 t1 full join ft
explain (verbose, costs off)
select array_agg(distinct (t1.c1)%5 order by (t1.c1)%5 desc nulls last) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) where t1.c1 < 20 or (t1.c1 is null and t2.c1 < 5) group by (t2.c1)%3 order by 1;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sort
Output: (array_agg(DISTINCT (t1.c1 % 5) ORDER BY (t1.c1 % 5) DESC NULLS LAST)), ((t2.c1 % 3))
Sort Key: (array_agg(DISTINCT (t1.c1 % 5) ORDER BY (t1.c1 % 5) DESC NULLS LAST))
-> Foreign Scan
Output: (array_agg(DISTINCT (t1.c1 % 5) ORDER BY (t1.c1 % 5) DESC NULLS LAST)), ((t2.c1 % 3))
Relations: Aggregate on ((public.ft4 t1) FULL JOIN (public.ft5 t2))
Remote SQL: SELECT array_agg(DISTINCT (r1.c1 % 5) ORDER BY ((r1.c1 % 5)) DESC NULLS LAST), (r2.c1 % 3) FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) WHERE (((r1.c1 < 20) OR ((r1.c1 IS NULL) AND (r2.c1 < 5)))) GROUP BY ((r2.c1 % 3))
Remote SQL: SELECT array_agg(DISTINCT (r1.c1 % 5) ORDER BY ((r1.c1 % 5)) DESC NULLS LAST), (r2.c1 % 3) FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) WHERE (((r1.c1 < 20) OR ((r1.c1 IS NULL) AND (r2.c1 < 5)))) GROUP BY 2
(7 rows)
select array_agg(distinct (t1.c1)%5 order by (t1.c1)%5 desc nulls last) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) where t1.c1 < 20 or (t1.c1 is null and t2.c1 < 5) group by (t2.c1)%3 order by 1;
......@@ -2818,15 +2841,15 @@ select array_agg(distinct (t1.c1)%5 order by (t1.c1)%5 desc nulls last) from ft4
-- FILTER within aggregate
explain (verbose, costs off)
select sum(c1) filter (where c1 < 100 and c2 > 5) from ft1 group by c2 order by 1 nulls last;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------
Sort
Output: (sum(c1) FILTER (WHERE ((c1 < 100) AND (c2 > 5)))), c2
Sort Key: (sum(ft1.c1) FILTER (WHERE ((ft1.c1 < 100) AND (ft1.c2 > 5))))
-> Foreign Scan
Output: (sum(c1) FILTER (WHERE ((c1 < 100) AND (c2 > 5)))), c2
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT sum("C 1") FILTER (WHERE (("C 1" < 100) AND (c2 > 5))), c2 FROM "S 1"."T 1" GROUP BY c2
Remote SQL: SELECT sum("C 1") FILTER (WHERE (("C 1" < 100) AND (c2 > 5))), c2 FROM "S 1"."T 1" GROUP BY 2
(7 rows)
select sum(c1) filter (where c1 < 100 and c2 > 5) from ft1 group by c2 order by 1 nulls last;
......@@ -2847,12 +2870,12 @@ select sum(c1) filter (where c1 < 100 and c2 > 5) from ft1 group by c2 order by
-- DISTINCT, ORDER BY and FILTER within aggregate
explain (verbose, costs off)
select sum(c1%3), sum(distinct c1%3 order by c1%3) filter (where c1%3 < 2), c2 from ft1 where c2 = 6 group by c2;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: (sum((c1 % 3))), (sum(DISTINCT (c1 % 3) ORDER BY (c1 % 3)) FILTER (WHERE ((c1 % 3) < 2))), c2
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT sum(("C 1" % 3)), sum(DISTINCT ("C 1" % 3) ORDER BY (("C 1" % 3)) ASC NULLS LAST) FILTER (WHERE (("C 1" % 3) < 2)), c2 FROM "S 1"."T 1" WHERE ((c2 = 6)) GROUP BY c2
Remote SQL: SELECT sum(("C 1" % 3)), sum(DISTINCT ("C 1" % 3) ORDER BY (("C 1" % 3)) ASC NULLS LAST) FILTER (WHERE (("C 1" % 3) < 2)), c2 FROM "S 1"."T 1" WHERE ((c2 = 6)) GROUP BY 3
(4 rows)
select sum(c1%3), sum(distinct c1%3 order by c1%3) filter (where c1%3 < 2), c2 from ft1 where c2 = 6 group by c2;
......@@ -2948,15 +2971,15 @@ select sum(c2) filter (where c2 in (select c2 from ft1 where c2 < 5)) from ft1;
-- Ordered-sets within aggregate
explain (verbose, costs off)
select c2, rank('10'::varchar) within group (order by c6), percentile_cont(c2/10::numeric) within group (order by c1) from ft1 where c2 < 10 group by c2 having percentile_cont(c2/10::numeric) within group (order by c1) < 500 order by c2;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sort
Output: c2, (rank('10'::character varying) WITHIN GROUP (ORDER BY c6)), (percentile_cont((((c2)::numeric / '10'::numeric))::double precision) WITHIN GROUP (ORDER BY ((c1)::double precision)))
Sort Key: ft1.c2
-> Foreign Scan
Output: c2, (rank('10'::character varying) WITHIN GROUP (ORDER BY c6)), (percentile_cont((((c2)::numeric / '10'::numeric))::double precision) WITHIN GROUP (ORDER BY ((c1)::double precision)))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, rank('10'::character varying) WITHIN GROUP (ORDER BY c6 ASC NULLS LAST), percentile_cont((c2 / 10::numeric)) WITHIN GROUP (ORDER BY ("C 1") ASC NULLS LAST) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY c2 HAVING ((percentile_cont((c2 / 10::numeric)) WITHIN GROUP (ORDER BY ("C 1") ASC NULLS LAST) < 500::double precision))
Remote SQL: SELECT c2, rank('10'::character varying) WITHIN GROUP (ORDER BY c6 ASC NULLS LAST), percentile_cont((c2 / 10::numeric)) WITHIN GROUP (ORDER BY ("C 1") ASC NULLS LAST) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY 1 HAVING ((percentile_cont((c2 / 10::numeric)) WITHIN GROUP (ORDER BY ("C 1") ASC NULLS LAST) < 500::double precision))
(7 rows)
select c2, rank('10'::varchar) within group (order by c6), percentile_cont(c2/10::numeric) within group (order by c1) from ft1 where c2 < 10 group by c2 having percentile_cont(c2/10::numeric) within group (order by c1) < 500 order by c2;
......@@ -2972,12 +2995,12 @@ select c2, rank('10'::varchar) within group (order by c6), percentile_cont(c2/10
-- Using multiple arguments within aggregates
explain (verbose, costs off)
select c1, rank(c1, c2) within group (order by c1, c2) from ft1 group by c1, c2 having c1 = 6 order by 1;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: c1, (rank(c1, c2) WITHIN GROUP (ORDER BY c1, c2)), c2
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT "C 1", rank("C 1", c2) WITHIN GROUP (ORDER BY "C 1" ASC NULLS LAST, c2 ASC NULLS LAST), c2 FROM "S 1"."T 1" WHERE (("C 1" = 6)) GROUP BY "C 1", c2
Remote SQL: SELECT "C 1", rank("C 1", c2) WITHIN GROUP (ORDER BY "C 1" ASC NULLS LAST, c2 ASC NULLS LAST), c2 FROM "S 1"."T 1" WHERE (("C 1" = 6)) GROUP BY 1, 3
(4 rows)
select c1, rank(c1, c2) within group (order by c1, c2) from ft1 group by c1, c2 having c1 = 6 order by 1;
......@@ -3015,15 +3038,15 @@ alter server loopback options (set extensions 'postgres_fdw');
-- Now aggregate will be pushed. Aggregate will display VARIADIC argument.
explain (verbose, costs off)
select c2, least_agg(c1) from ft1 where c2 < 100 group by c2 order by c2;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------
Sort
Output: c2, (least_agg(VARIADIC ARRAY[c1]))
Sort Key: ft1.c2
-> Foreign Scan
Output: c2, (least_agg(VARIADIC ARRAY[c1]))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, public.least_agg(VARIADIC ARRAY["C 1"]) FROM "S 1"."T 1" WHERE ((c2 < 100)) GROUP BY c2
Remote SQL: SELECT c2, public.least_agg(VARIADIC ARRAY["C 1"]) FROM "S 1"."T 1" WHERE ((c2 < 100)) GROUP BY 1
(7 rows)
select c2, least_agg(c1) from ft1 where c2 < 100 group by c2 order by c2;
......@@ -3115,12 +3138,12 @@ alter server loopback options (set extensions 'postgres_fdw');
-- Now this will be pushed as sort operator is part of the extension.
explain (verbose, costs off)
select array_agg(c1 order by c1 using operator(public.<^)) from ft2 where c2 = 6 and c1 < 100 group by c2;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: (array_agg(c1 ORDER BY c1 USING <^ NULLS LAST)), c2
Relations: Aggregate on (public.ft2)
Remote SQL: SELECT array_agg("C 1" ORDER BY "C 1" USING OPERATOR(public.<^) NULLS LAST), c2 FROM "S 1"."T 1" WHERE (("C 1" < 100)) AND ((c2 = 6)) GROUP BY c2
Remote SQL: SELECT array_agg("C 1" ORDER BY "C 1" USING OPERATOR(public.<^) NULLS LAST), c2 FROM "S 1"."T 1" WHERE (("C 1" < 100)) AND ((c2 = 6)) GROUP BY 2
(4 rows)
select array_agg(c1 order by c1 using operator(public.<^)) from ft2 where c2 = 6 and c1 < 100 group by c2;
......@@ -3181,8 +3204,8 @@ select count(t1.c3) from ft2 t1 left join ft2 t2 on (t1.c1 = random() * t2.c2);
-- Subquery in FROM clause having aggregate
explain (verbose, costs off)
select count(*), x.b from ft1, (select c2 a, sum(c1) b from ft1 group by c2) x where ft1.c2 = x.a group by x.b order by 1, 2;
QUERY PLAN
------------------------------------------------------------------------------------------------
QUERY PLAN
-----------------------------------------------------------------------------------------------
Sort
Output: (count(*)), x.b
Sort Key: (count(*)), x.b
......@@ -3203,7 +3226,7 @@ select count(*), x.b from ft1, (select c2 a, sum(c1) b from ft1 group by c2) x w
-> Foreign Scan
Output: ft1_1.c2, (sum(ft1_1.c1))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, sum("C 1") FROM "S 1"."T 1" GROUP BY c2
Remote SQL: SELECT c2, sum("C 1") FROM "S 1"."T 1" GROUP BY 1
(21 rows)
select count(*), x.b from ft1, (select c2 a, sum(c1) b from ft1 group by c2) x where ft1.c2 = x.a group by x.b order by 1, 2;
......@@ -3224,15 +3247,15 @@ select count(*), x.b from ft1, (select c2 a, sum(c1) b from ft1 group by c2) x w
-- FULL join with IS NULL check in HAVING
explain (verbose, costs off)
select avg(t1.c1), sum(t2.c1) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) group by t2.c1 having (avg(t1.c1) is null and sum(t2.c1) < 10) or sum(t2.c1) is null order by 1 nulls last, 2;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sort
Output: (avg(t1.c1)), (sum(t2.c1)), t2.c1
Sort Key: (avg(t1.c1)), (sum(t2.c1))
-> Foreign Scan
Output: (avg(t1.c1)), (sum(t2.c1)), t2.c1
Relations: Aggregate on ((public.ft4 t1) FULL JOIN (public.ft5 t2))
Remote SQL: SELECT avg(r1.c1), sum(r2.c1), r2.c1 FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) GROUP BY r2.c1 HAVING ((((avg(r1.c1) IS NULL) AND (sum(r2.c1) < 10)) OR (sum(r2.c1) IS NULL)))
Remote SQL: SELECT avg(r1.c1), sum(r2.c1), r2.c1 FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) GROUP BY 3 HAVING ((((avg(r1.c1) IS NULL) AND (sum(r2.c1) < 10)) OR (sum(r2.c1) IS NULL)))
(7 rows)
select avg(t1.c1), sum(t2.c1) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) group by t2.c1 having (avg(t1.c1) is null and sum(t2.c1) < 10) or sum(t2.c1) is null order by 1 nulls last, 2;
......@@ -3286,8 +3309,8 @@ select sum(c2) * (random() <= 1)::int as sum from ft1 order by 1;
set enable_hashagg to false;
explain (verbose, costs off)
select c2, sum from "S 1"."T 1" t1, lateral (select sum(t2.c1 + t1."C 1") sum from ft2 t2 group by t2.c1) qry where t1.c2 * 2 = qry.sum and t1.c2 < 3 and t1."C 1" < 100 order by 1;
QUERY PLAN
----------------------------------------------------------------------------------------------------------
QUERY PLAN
------------------------------------------------------------------------------------------------------
Sort
Output: t1.c2, qry.sum
Sort Key: t1.c2
......@@ -3303,7 +3326,7 @@ select c2, sum from "S 1"."T 1" t1, lateral (select sum(t2.c1 + t1."C 1") sum fr
-> Foreign Scan
Output: (sum((t2.c1 + t1."C 1"))), t2.c1
Relations: Aggregate on (public.ft2 t2)
Remote SQL: SELECT sum(("C 1" + $1::integer)), "C 1" FROM "S 1"."T 1" GROUP BY "C 1"
Remote SQL: SELECT sum(("C 1" + $1::integer)), "C 1" FROM "S 1"."T 1" GROUP BY 2
(16 rows)
select c2, sum from "S 1"."T 1" t1, lateral (select sum(t2.c1 + t1."C 1") sum from ft2 t2 group by t2.c1) qry where t1.c2 * 2 = qry.sum and t1.c2 < 3 and t1."C 1" < 100 order by 1;
......@@ -3449,8 +3472,8 @@ select c2, sum(c1), grouping(c2) from ft1 where c2 < 3 group by c2 order by 1 nu
-- DISTINCT itself is not pushed down, whereas underneath aggregate is pushed
explain (verbose, costs off)
select distinct sum(c1)/1000 s from ft2 where c2 < 6 group by c2 order by 1;
QUERY PLAN
--------------------------------------------------------------------------------------------------------
QUERY PLAN
-------------------------------------------------------------------------------------------------------
Unique
Output: ((sum(c1) / 1000)), c2
-> Sort
......@@ -3459,7 +3482,7 @@ select distinct sum(c1)/1000 s from ft2 where c2 < 6 group by c2 order by 1;
-> Foreign Scan
Output: ((sum(c1) / 1000)), c2
Relations: Aggregate on (public.ft2)
Remote SQL: SELECT (sum("C 1") / 1000), c2 FROM "S 1"."T 1" WHERE ((c2 < 6)) GROUP BY c2
Remote SQL: SELECT (sum("C 1") / 1000), c2 FROM "S 1"."T 1" WHERE ((c2 < 6)) GROUP BY 2
(9 rows)
select distinct sum(c1)/1000 s from ft2 where c2 < 6 group by c2 order by 1;
......@@ -3472,8 +3495,8 @@ select distinct sum(c1)/1000 s from ft2 where c2 < 6 group by c2 order by 1;
-- WindowAgg
explain (verbose, costs off)
select c2, sum(c2), count(c2) over (partition by c2%2) from ft2 where c2 < 10 group by c2 order by 1;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------
QUERY PLAN
------------------------------------------------------------------------------------------------------------
Sort
Output: c2, (sum(c2)), (count(c2) OVER (?)), ((c2 % 2))
Sort Key: ft2.c2
......@@ -3485,7 +3508,7 @@ select c2, sum(c2), count(c2) over (partition by c2%2) from ft2 where c2 < 10 gr
-> Foreign Scan
Output: c2, ((c2 % 2)), (sum(c2))
Relations: Aggregate on (public.ft2)
Remote SQL: SELECT c2, (c2 % 2), sum(c2) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY c2
Remote SQL: SELECT c2, (c2 % 2), sum(c2) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY 1
(12 rows)
select c2, sum(c2), count(c2) over (partition by c2%2) from ft2 where c2 < 10 group by c2 order by 1;
......@@ -3505,8 +3528,8 @@ select c2, sum(c2), count(c2) over (partition by c2%2) from ft2 where c2 < 10 gr
explain (verbose, costs off)
select c2, array_agg(c2) over (partition by c2%2 order by c2 desc) from ft1 where c2 < 10 group by c2 order by 1;
QUERY PLAN
----------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------------
Sort
Output: c2, (array_agg(c2) OVER (?)), ((c2 % 2))
Sort Key: ft1.c2
......@@ -3518,7 +3541,7 @@ select c2, array_agg(c2) over (partition by c2%2 order by c2 desc) from ft1 wher
-> Foreign Scan
Output: c2, ((c2 % 2))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, (c2 % 2) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY c2
Remote SQL: SELECT c2, (c2 % 2) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY 1
(12 rows)
select c2, array_agg(c2) over (partition by c2%2 order by c2 desc) from ft1 where c2 < 10 group by c2 order by 1;
......@@ -3538,8 +3561,8 @@ select c2, array_agg(c2) over (partition by c2%2 order by c2 desc) from ft1 wher
explain (verbose, costs off)
select c2, array_agg(c2) over (partition by c2%2 order by c2 range between current row and unbounded following) from ft1 where c2 < 10 group by c2 order by 1;
QUERY PLAN
----------------------------------------------------------------------------------------------------
QUERY PLAN
---------------------------------------------------------------------------------------------------
Sort
Output: c2, (array_agg(c2) OVER (?)), ((c2 % 2))
Sort Key: ft1.c2
......@@ -3551,7 +3574,7 @@ select c2, array_agg(c2) over (partition by c2%2 order by c2 range between curre
-> Foreign Scan
Output: c2, ((c2 % 2))
Relations: Aggregate on (public.ft1)
Remote SQL: SELECT c2, (c2 % 2) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY c2
Remote SQL: SELECT c2, (c2 % 2) FROM "S 1"."T 1" WHERE ((c2 < 10)) GROUP BY 1
(12 rows)
select c2, array_agg(c2) over (partition by c2%2 order by c2 range between current row and unbounded following) from ft1 where c2 < 10 group by c2 order by 1;
......
contrib/postgres_fdw/postgres_fdw.c
View file @ e9f2703a
......@@ -4591,7 +4591,7 @@ static bool
foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
{
Query *query = root->parse;
PathTarget *grouping_target;
PathTarget *grouping_target = root->upper_targets[UPPERREL_GROUP_AGG];
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) grouped_rel->fdw_private;
PgFdwRelationInfo *ofpinfo;
List *aggvars;
......@@ -4599,7 +4599,7 @@ foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
int i;
List *tlist = NIL;
/* Grouping Sets are not pushable */
/* We currently don't support pushing Grouping Sets. */
if (query->groupingSets)
return false;
......@@ -4607,7 +4607,7 @@ foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
/*
* If underneath input relation has any local conditions, those conditions
* If underlying scan relation has any local conditions, those conditions
* are required to be applied before performing aggregation. Hence the
* aggregate cannot be pushed down.
*/
......@@ -4615,21 +4615,11 @@ foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
return false;
/*
* The targetlist expected from this node and the targetlist pushed down
* to the foreign server may be different. The latter requires
* sortgrouprefs to be set to push down GROUP BY clause, but should not
* have those arising from ORDER BY clause. These sortgrouprefs may be
* different from those in the plan's targetlist. Use a copy of path
* target to record the new sortgrouprefs.
*/
grouping_target = copy_pathtarget(root->upper_targets[UPPERREL_GROUP_AGG]);
/*
* Evaluate grouping targets and check whether they are safe to push down
* to the foreign side. All GROUP BY expressions will be part of the
* grouping target and thus there is no need to evaluate it separately.
* While doing so, add required expressions into target list which can
* then be used to pass to foreign server.
* Examine grouping expressions, as well as other expressions we'd need to
* compute, and check whether they are safe to push down to the foreign
* server. All GROUP BY expressions will be part of the grouping target
* and thus there is no need to search for them separately. Add grouping
* expressions into target list which will be passed to foreign server.
*/
i = 0;
foreach(lc, grouping_target->exprs)
......@@ -4641,51 +4631,59 @@ foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
/* Check whether this expression is part of GROUP BY clause */
if (sgref && get_sortgroupref_clause_noerr(sgref, query->groupClause))
{
TargetEntry *tle;
/*
* If any of the GROUP BY expression is not shippable we can not
* If any GROUP BY expression is not shippable, then we cannot
* push down aggregation to the foreign server.
*/
if (!is_foreign_expr(root, grouped_rel, expr))
return false;
/* Pushable, add to tlist */
tlist = add_to_flat_tlist(tlist, list_make1(expr));
/*
* Pushable, so add to tlist. We need to create a TLE for this
* expression and apply the sortgroupref to it. We cannot use
* add_to_flat_tlist() here because that avoids making duplicate
* entries in the tlist. If there are duplicate entries with
* distinct sortgrouprefs, we have to duplicate that situation in
* the output tlist.
*/
tle = makeTargetEntry(expr, list_length(tlist) + 1, NULL, false);
tle->ressortgroupref = sgref;
tlist = lappend(tlist, tle);
}
else
{
/* Check entire expression whether it is pushable or not */
/*
* Non-grouping expression we need to compute. Is it shippable?
*/
if (is_foreign_expr(root, grouped_rel, expr))
{
/* Pushable, add to tlist */
/* Yes, so add to tlist as-is; OK to suppress duplicates */
tlist = add_to_flat_tlist(tlist, list_make1(expr));
}
else
{
/*
* If we have sortgroupref set, then it means that we have an
* ORDER BY entry pointing to this expression. Since we are
* not pushing ORDER BY with GROUP BY, clear it.
*/
if (sgref)
grouping_target->sortgrouprefs[i] = 0;
/* Not matched exactly, pull the var with aggregates then */
/* Not pushable as a whole; extract its Vars and aggregates */
aggvars = pull_var_clause((Node *) expr,
PVC_INCLUDE_AGGREGATES);
/*
* If any aggregate expression is not shippable, then we
* cannot push down aggregation to the foreign server.
*/
if (!is_foreign_expr(root, grouped_rel, (Expr *) aggvars))
return false;
/*
* Add aggregates, if any, into the targetlist. Plain var
* nodes should be either same as some GROUP BY expression or
* part of some GROUP BY expression. In later case, the query
* cannot refer plain var nodes without the surrounding
* expression. In both the cases, they are already part of
* Add aggregates, if any, into the targetlist. Plain Vars
* outside an aggregate can be ignored, because they should be
* either same as some GROUP BY column or part of some GROUP
* BY expression. In either case, they are already part of
* the targetlist and thus no need to add them again. In fact
* adding pulled plain var nodes in SELECT clause will cause
* an error on the foreign server if they are not same as some
* GROUP BY expression.
* including plain Vars in the tlist when they do not match a
* GROUP BY column would cause the foreign server to complain
* that the shipped query is invalid.
*/
foreach(l, aggvars)
{
......@@ -4701,7 +4699,7 @@ foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
}
/*
* Classify the pushable and non-pushable having clauses and save them in
* Classify the pushable and non-pushable HAVING clauses and save them in
* remote_conds and local_conds of the grouped rel's fpinfo.
*/
if (root->hasHavingQual && query->havingQual)
......@@ -4771,9 +4769,6 @@ foreign_grouping_ok(PlannerInfo *root, RelOptInfo *grouped_rel)
}
}
/* Transfer any sortgroupref data to the replacement tlist */
apply_pathtarget_labeling_to_tlist(tlist, grouping_target);
/* Store generated targetlist */
fpinfo->grouped_tlist = tlist;
......
contrib/postgres_fdw/sql/postgres_fdw.sql
View file @ e9f2703a
......@@ -636,6 +636,12 @@ explain (verbose, costs off)
select count(c2) w, c2 x, 5 y, 7.0 z from ft1 group by 2, y, 9.0::int order by 2;
select count(c2) w, c2 x, 5 y, 7.0 z from ft1 group by 2, y, 9.0::int order by 2;
-- GROUP BY clause referring to same column multiple times
-- Also, ORDER BY contains an aggregate function
explain (verbose, costs off)
select c2, c2 from ft1 where c2 > 6 group by 1, 2 order by sum(c1);
select c2, c2 from ft1 where c2 > 6 group by 1, 2 order by sum(c1);
-- Testing HAVING clause shippability
explain (verbose, costs off)
select c2, sum(c1) from ft2 group by c2 having avg(c1) < 500 and sum(c1) < 49800 order by c2;
......
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