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Add support for deparsing semi-joins to contrib/postgres_fdw
SEMI-JOIN is deparsed as the EXISTS subquery. It references outer and inner relations, so it should be evaluated as the condition in the upper-level WHERE clause. The signatures of deparseFromExprForRel() and deparseRangeTblRef() are revised so that they can add conditions to the upper level. PgFdwRelationInfo now has a hidden_subquery_rels field, referencing the relids used in the inner parts of semi-join. They can't be referred to from upper relations and should be used internally for equivalence member searches. The planner can create semi-join, which refers to inner rel vars in its target list. However, we deparse semi-join as an exists() subquery. So we skip the case when the target list references to inner rel of semi-join. Author: Alexander Pyhalov Reviewed-by: Ashutosh Bapat, Ian Lawrence Barwick, Yuuki Fujii, Tomas Vondra Discussion: https://postgr.es/m/c9e2a757cf3ac2333714eaf83a9cc184@postgrespro.ru
This commit is contained in:
Alexander Korotkov
@ -2001,23 +2001,16 @@ SELECT t1.ctid, t1, t2, t1.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER B
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Remote SQL: SELECT r1.ctid, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END, r1."C 1", r1.c3 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r1."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint
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(4 rows)
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-- SEMI JOIN, not pushed down
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-- SEMI JOIN
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EXPLAIN (VERBOSE, COSTS OFF)
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SELECT t1.c1 FROM ft1 t1 WHERE EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c1) ORDER BY t1.c1 OFFSET 100 LIMIT 10;
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QUERY PLAN
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---------------------------------------------------------------------------------------
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Limit
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QUERY PLAN
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-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: t1.c1
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-> Merge Semi Join
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Output: t1.c1
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Merge Cond: (t1.c1 = t2.c1)
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-> Foreign Scan on public.ft1 t1
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Output: t1.c1
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Remote SQL: SELECT "C 1" FROM "S 1"."T 1" ORDER BY "C 1" ASC NULLS LAST
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-> Foreign Scan on public.ft2 t2
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Output: t2.c1
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Remote SQL: SELECT "C 1" FROM "S 1"."T 1" ORDER BY "C 1" ASC NULLS LAST
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(11 rows)
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Relations: (public.ft1 t1) SEMI JOIN (public.ft2 t2)
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Remote SQL: SELECT r1."C 1" FROM "S 1"."T 1" r1 WHERE EXISTS (SELECT NULL FROM "S 1"."T 1" r2 WHERE ((r2."C 1" = r1."C 1"))) ORDER BY r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint
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(4 rows)
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SELECT t1.c1 FROM ft1 t1 WHERE EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c1) ORDER BY t1.c1 OFFSET 100 LIMIT 10;
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c1
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@ -4056,23 +4049,13 @@ RESET enable_sort;
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-- subquery using immutable function (can be sent to remote)
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PREPARE st3(int) AS SELECT * FROM ft1 t1 WHERE t1.c1 < $2 AND t1.c3 IN (SELECT c3 FROM ft2 t2 WHERE c1 > $1 AND date(c5) = '1970-01-17'::date) ORDER BY c1;
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EXPLAIN (VERBOSE, COSTS OFF) EXECUTE st3(10, 20);
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QUERY PLAN
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-----------------------------------------------------------------------------------------------------------------------
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Sort
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QUERY PLAN
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-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: t1.c1, t1.c2, t1.c3, t1.c4, t1.c5, t1.c6, t1.c7, t1.c8
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Sort Key: t1.c1
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-> Nested Loop Semi Join
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Output: t1.c1, t1.c2, t1.c3, t1.c4, t1.c5, t1.c6, t1.c7, t1.c8
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Join Filter: (t2.c3 = t1.c3)
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-> Foreign Scan on public.ft1 t1
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Output: t1.c1, t1.c2, t1.c3, t1.c4, t1.c5, t1.c6, t1.c7, t1.c8
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Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" < 20))
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-> Materialize
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Output: t2.c3
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-> Foreign Scan on public.ft2 t2
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Output: t2.c3
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Remote SQL: SELECT c3 FROM "S 1"."T 1" WHERE (("C 1" > 10)) AND ((date(c5) = '1970-01-17'::date))
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(14 rows)
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Relations: (public.ft1 t1) SEMI JOIN (public.ft2 t2)
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Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8 FROM "S 1"."T 1" r1 WHERE ((r1."C 1" < 20)) AND EXISTS (SELECT NULL FROM "S 1"."T 1" r3 WHERE ((r3."C 1" > 10)) AND ((date(r3.c5) = '1970-01-17'::date)) AND ((r3.c3 = r1.c3))) ORDER BY r1."C 1" ASC NULLS LAST
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(4 rows)
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EXECUTE st3(10, 20);
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c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
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@ -4616,6 +4599,283 @@ explain (verbose, costs off) select * from ft3 f, loct3 l
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Index Cond: (l.f1 = 'foo'::text)
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(12 rows)
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-- ===================================================================
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-- test SEMI-JOIN pushdown
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-- ===================================================================
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EXPLAIN (verbose, costs off)
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SELECT ft2.*, ft4.* FROM ft2 INNER JOIN ft4 ON ft2.c2 = ft4.c1
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WHERE ft2.c1 > 900
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AND EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)
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ORDER BY ft2.c1;
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QUERY PLAN
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-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3
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Relations: ((public.ft2) INNER JOIN (public.ft4)) SEMI JOIN (public.ft5)
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Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, r2.c1, r2.c2, r2.c3 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 3" r2 ON (((r1.c2 = r2.c1)) AND ((r1."C 1" > 900)))) WHERE EXISTS (SELECT NULL FROM "S 1"."T 4" r4 WHERE ((r1.c2 = r4.c1))) ORDER BY r1."C 1" ASC NULLS LAST
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(4 rows)
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SELECT ft2.*, ft4.* FROM ft2 INNER JOIN ft4 ON ft2.c2 = ft4.c1
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WHERE ft2.c1 > 900
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AND EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)
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ORDER BY ft2.c1;
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c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3
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-----+----+-------+------------------------------+--------------------------+----+------------+-----+----+----+--------
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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916 | 6 | 00916 | Sat Jan 17 00:00:00 1970 PST | Sat Jan 17 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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926 | 6 | 00926 | Tue Jan 27 00:00:00 1970 PST | Tue Jan 27 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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936 | 6 | 00936 | Fri Feb 06 00:00:00 1970 PST | Fri Feb 06 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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946 | 6 | 00946 | Mon Feb 16 00:00:00 1970 PST | Mon Feb 16 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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956 | 6 | 00956 | Thu Feb 26 00:00:00 1970 PST | Thu Feb 26 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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966 | 6 | 00966 | Sun Mar 08 00:00:00 1970 PST | Sun Mar 08 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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976 | 6 | 00976 | Wed Mar 18 00:00:00 1970 PST | Wed Mar 18 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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986 | 6 | 00986 | Sat Mar 28 00:00:00 1970 PST | Sat Mar 28 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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996 | 6 | 00996 | Tue Apr 07 00:00:00 1970 PST | Tue Apr 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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(10 rows)
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-- The same query, different join order
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EXPLAIN (verbose, costs off)
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SELECT ft2.*, ft4.* FROM ft2 INNER JOIN
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(SELECT * FROM ft4 WHERE
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EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)) ft4
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ON ft2.c2 = ft4.c1
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WHERE ft2.c1 > 900
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ORDER BY ft2.c1;
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QUERY PLAN
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-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3
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Relations: ((public.ft2) INNER JOIN (public.ft4)) SEMI JOIN (public.ft5)
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Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, r4.c1, r4.c2, r4.c3 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 3" r4 ON (((r1.c2 = r4.c1)) AND ((r1."C 1" > 900)))) WHERE EXISTS (SELECT NULL FROM "S 1"."T 4" r5 WHERE ((r4.c1 = r5.c1))) ORDER BY r1."C 1" ASC NULLS LAST
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(4 rows)
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SELECT ft2.*, ft4.* FROM ft2 INNER JOIN
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(SELECT * FROM ft4 WHERE
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EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)) ft4
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ON ft2.c2 = ft4.c1
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WHERE ft2.c1 > 900
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ORDER BY ft2.c1;
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c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3
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-----+----+-------+------------------------------+--------------------------+----+------------+-----+----+----+--------
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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916 | 6 | 00916 | Sat Jan 17 00:00:00 1970 PST | Sat Jan 17 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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926 | 6 | 00926 | Tue Jan 27 00:00:00 1970 PST | Tue Jan 27 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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936 | 6 | 00936 | Fri Feb 06 00:00:00 1970 PST | Fri Feb 06 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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946 | 6 | 00946 | Mon Feb 16 00:00:00 1970 PST | Mon Feb 16 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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956 | 6 | 00956 | Thu Feb 26 00:00:00 1970 PST | Thu Feb 26 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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966 | 6 | 00966 | Sun Mar 08 00:00:00 1970 PST | Sun Mar 08 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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976 | 6 | 00976 | Wed Mar 18 00:00:00 1970 PST | Wed Mar 18 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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986 | 6 | 00986 | Sat Mar 28 00:00:00 1970 PST | Sat Mar 28 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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996 | 6 | 00996 | Tue Apr 07 00:00:00 1970 PST | Tue Apr 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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(10 rows)
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-- Left join
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EXPLAIN (verbose, costs off)
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SELECT ft2.*, ft4.* FROM ft2 LEFT JOIN
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(SELECT * FROM ft4 WHERE
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EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)) ft4
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ON ft2.c2 = ft4.c1
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WHERE ft2.c1 > 900
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ORDER BY ft2.c1 LIMIT 10;
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QUERY PLAN
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------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3
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Relations: (public.ft2) LEFT JOIN ((public.ft4) SEMI JOIN (public.ft5))
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Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, s6.c1, s6.c2, s6.c3 FROM ("S 1"."T 1" r1 LEFT JOIN (SELECT r4.c1, r4.c2, r4.c3 FROM "S 1"."T 3" r4 WHERE EXISTS (SELECT NULL FROM "S 1"."T 4" r5 WHERE ((r4.c1 = r5.c1)))) s6(c1, c2, c3) ON (((r1.c2 = s6.c1)))) WHERE ((r1."C 1" > 900)) ORDER BY r1."C 1" ASC NULLS LAST LIMIT 10::bigint
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(4 rows)
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SELECT ft2.*, ft4.* FROM ft2 LEFT JOIN
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(SELECT * FROM ft4 WHERE
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EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)) ft4
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ON ft2.c2 = ft4.c1
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WHERE ft2.c1 > 900
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ORDER BY ft2.c1 LIMIT 10;
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c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3
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-----+----+-------+------------------------------+--------------------------+----+------------+-----+----+----+--------
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901 | 1 | 00901 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo | | |
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902 | 2 | 00902 | Sat Jan 03 00:00:00 1970 PST | Sat Jan 03 00:00:00 1970 | 2 | 2 | foo | | |
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903 | 3 | 00903 | Sun Jan 04 00:00:00 1970 PST | Sun Jan 04 00:00:00 1970 | 3 | 3 | foo | | |
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904 | 4 | 00904 | Mon Jan 05 00:00:00 1970 PST | Mon Jan 05 00:00:00 1970 | 4 | 4 | foo | | |
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905 | 5 | 00905 | Tue Jan 06 00:00:00 1970 PST | Tue Jan 06 00:00:00 1970 | 5 | 5 | foo | | |
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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907 | 7 | 00907 | Thu Jan 08 00:00:00 1970 PST | Thu Jan 08 00:00:00 1970 | 7 | 7 | foo | | |
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908 | 8 | 00908 | Fri Jan 09 00:00:00 1970 PST | Fri Jan 09 00:00:00 1970 | 8 | 8 | foo | | |
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909 | 9 | 00909 | Sat Jan 10 00:00:00 1970 PST | Sat Jan 10 00:00:00 1970 | 9 | 9 | foo | | |
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910 | 0 | 00910 | Sun Jan 11 00:00:00 1970 PST | Sun Jan 11 00:00:00 1970 | 0 | 0 | foo | | |
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(10 rows)
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-- Several semi-joins per upper level join
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EXPLAIN (verbose, costs off)
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SELECT ft2.*, ft4.* FROM ft2 INNER JOIN
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(SELECT * FROM ft4 WHERE
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EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)) ft4
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ON ft2.c2 = ft4.c1
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INNER JOIN (SELECT * FROM ft5 WHERE
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EXISTS (SELECT 1 FROM ft4 WHERE ft4.c1 = ft5.c1)) ft5
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ON ft2.c2 <= ft5.c1
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WHERE ft2.c1 > 900
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ORDER BY ft2.c1 LIMIT 10;
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QUERY PLAN
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-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3
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Relations: ((((public.ft2) INNER JOIN (public.ft4)) SEMI JOIN (public.ft5)) INNER JOIN (public.ft5 ft5_1)) SEMI JOIN (public.ft4 ft4_1)
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Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, r6.c1, r6.c2, r6.c3 FROM (("S 1"."T 1" r1 INNER JOIN "S 1"."T 3" r6 ON (((r1.c2 = r6.c1)) AND ((r1."C 1" > 900)))) INNER JOIN "S 1"."T 4" r8 ON (((r1.c2 <= r8.c1)))) WHERE EXISTS (SELECT NULL FROM "S 1"."T 3" r9 WHERE ((r8.c1 = r9.c1))) AND EXISTS (SELECT NULL FROM "S 1"."T 4" r7 WHERE ((r6.c1 = r7.c1))) ORDER BY r1."C 1" ASC NULLS LAST LIMIT 10::bigint
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(4 rows)
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SELECT ft2.*, ft4.* FROM ft2 INNER JOIN
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(SELECT * FROM ft4 WHERE
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EXISTS (SELECT 1 FROM ft5 WHERE ft4.c1 = ft5.c1)) ft4
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ON ft2.c2 = ft4.c1
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INNER JOIN (SELECT * FROM ft5 WHERE
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EXISTS (SELECT 1 FROM ft4 WHERE ft4.c1 = ft5.c1)) ft5
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ON ft2.c2 <= ft5.c1
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WHERE ft2.c1 > 900
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ORDER BY ft2.c1 LIMIT 10;
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c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3
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-----+----+-------+------------------------------+--------------------------+----+------------+-----+----+----+--------
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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906 | 6 | 00906 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6 | 6 | foo | 6 | 7 | AAA006
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(10 rows)
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-- Semi-join below Semi-join
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EXPLAIN (verbose, costs off)
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SELECT ft2.* FROM ft2 WHERE
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c1 = ANY (
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SELECT c1 FROM ft2 WHERE
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EXISTS (SELECT 1 FROM ft4 WHERE ft4.c2 = ft2.c2))
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AND ft2.c1 > 900
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ORDER BY ft2.c1 LIMIT 10;
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QUERY PLAN
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-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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Foreign Scan
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Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8
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Relations: (public.ft2) SEMI JOIN ((public.ft2 ft2_1) SEMI JOIN (public.ft4))
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Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8 FROM "S 1"."T 1" r1 WHERE ((r1."C 1" > 900)) AND EXISTS (SELECT NULL FROM "S 1"."T 1" r3 WHERE ((r1."C 1" = r3."C 1")) AND EXISTS (SELECT NULL FROM "S 1"."T 3" r4 WHERE ((r3.c2 = r4.c2)))) ORDER BY r1."C 1" ASC NULLS LAST LIMIT 10::bigint
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(4 rows)
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SELECT ft2.* FROM ft2 WHERE
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c1 = ANY (
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SELECT c1 FROM ft2 WHERE
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EXISTS (SELECT 1 FROM ft4 WHERE ft4.c2 = ft2.c2))
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AND ft2.c1 > 900
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ORDER BY ft2.c1 LIMIT 10;
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c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
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-----+----+-------+------------------------------+--------------------------+----+------------+-----
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903 | 3 | 00903 | Sun Jan 04 00:00:00 1970 PST | Sun Jan 04 00:00:00 1970 | 3 | 3 | foo
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||||
905 | 5 | 00905 | Tue Jan 06 00:00:00 1970 PST | Tue Jan 06 00:00:00 1970 | 5 | 5 | foo
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907 | 7 | 00907 | Thu Jan 08 00:00:00 1970 PST | Thu Jan 08 00:00:00 1970 | 7 | 7 | foo
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909 | 9 | 00909 | Sat Jan 10 00:00:00 1970 PST | Sat Jan 10 00:00:00 1970 | 9 | 9 | foo
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||||
913 | 3 | 00913 | Wed Jan 14 00:00:00 1970 PST | Wed Jan 14 00:00:00 1970 | 3 | 3 | foo
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915 | 5 | 00915 | Fri Jan 16 00:00:00 1970 PST | Fri Jan 16 00:00:00 1970 | 5 | 5 | foo
|
||||
917 | 7 | 00917 | Sun Jan 18 00:00:00 1970 PST | Sun Jan 18 00:00:00 1970 | 7 | 7 | foo
|
||||
919 | 9 | 00919 | Tue Jan 20 00:00:00 1970 PST | Tue Jan 20 00:00:00 1970 | 9 | 9 | foo
|
||||
923 | 3 | 00923 | Sat Jan 24 00:00:00 1970 PST | Sat Jan 24 00:00:00 1970 | 3 | 3 | foo
|
||||
925 | 5 | 00925 | Mon Jan 26 00:00:00 1970 PST | Mon Jan 26 00:00:00 1970 | 5 | 5 | foo
|
||||
(10 rows)
|
||||
|
||||
-- Upper level relations shouldn't refer EXISTS() subqueries
|
||||
EXPLAIN (verbose, costs off)
|
||||
SELECT * FROM ft2 ftupper WHERE
|
||||
EXISTS (
|
||||
SELECT c1 FROM ft2 WHERE
|
||||
EXISTS (SELECT 1 FROM ft4 WHERE ft4.c2 = ft2.c2) AND c1 = ftupper.c1 )
|
||||
AND ftupper.c1 > 900
|
||||
ORDER BY ftupper.c1 LIMIT 10;
|
||||
QUERY PLAN
|
||||
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
||||
Foreign Scan
|
||||
Output: ftupper.c1, ftupper.c2, ftupper.c3, ftupper.c4, ftupper.c5, ftupper.c6, ftupper.c7, ftupper.c8
|
||||
Relations: (public.ft2 ftupper) SEMI JOIN ((public.ft2) SEMI JOIN (public.ft4))
|
||||
Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8 FROM "S 1"."T 1" r1 WHERE ((r1."C 1" > 900)) AND EXISTS (SELECT NULL FROM "S 1"."T 1" r2 WHERE ((r1."C 1" = r2."C 1")) AND EXISTS (SELECT NULL FROM "S 1"."T 3" r3 WHERE ((r2.c2 = r3.c2)))) ORDER BY r1."C 1" ASC NULLS LAST LIMIT 10::bigint
|
||||
(4 rows)
|
||||
|
||||
SELECT * FROM ft2 ftupper WHERE
|
||||
EXISTS (
|
||||
SELECT c1 FROM ft2 WHERE
|
||||
EXISTS (SELECT 1 FROM ft4 WHERE ft4.c2 = ft2.c2) AND c1 = ftupper.c1 )
|
||||
AND ftupper.c1 > 900
|
||||
ORDER BY ftupper.c1 LIMIT 10;
|
||||
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
|
||||
-----+----+-------+------------------------------+--------------------------+----+------------+-----
|
||||
903 | 3 | 00903 | Sun Jan 04 00:00:00 1970 PST | Sun Jan 04 00:00:00 1970 | 3 | 3 | foo
|
||||
905 | 5 | 00905 | Tue Jan 06 00:00:00 1970 PST | Tue Jan 06 00:00:00 1970 | 5 | 5 | foo
|
||||
907 | 7 | 00907 | Thu Jan 08 00:00:00 1970 PST | Thu Jan 08 00:00:00 1970 | 7 | 7 | foo
|
||||
909 | 9 | 00909 | Sat Jan 10 00:00:00 1970 PST | Sat Jan 10 00:00:00 1970 | 9 | 9 | foo
|
||||
913 | 3 | 00913 | Wed Jan 14 00:00:00 1970 PST | Wed Jan 14 00:00:00 1970 | 3 | 3 | foo
|
||||
915 | 5 | 00915 | Fri Jan 16 00:00:00 1970 PST | Fri Jan 16 00:00:00 1970 | 5 | 5 | foo
|
||||
917 | 7 | 00917 | Sun Jan 18 00:00:00 1970 PST | Sun Jan 18 00:00:00 1970 | 7 | 7 | foo
|
||||
919 | 9 | 00919 | Tue Jan 20 00:00:00 1970 PST | Tue Jan 20 00:00:00 1970 | 9 | 9 | foo
|
||||
923 | 3 | 00923 | Sat Jan 24 00:00:00 1970 PST | Sat Jan 24 00:00:00 1970 | 3 | 3 | foo
|
||||
925 | 5 | 00925 | Mon Jan 26 00:00:00 1970 PST | Mon Jan 26 00:00:00 1970 | 5 | 5 | foo
|
||||
(10 rows)
|
||||
|
||||
-- EXISTS should be propogated to the highest upper inner join
|
||||
EXPLAIN (verbose, costs off)
|
||||
SELECT ft2.*, ft4.* FROM ft2 INNER JOIN
|
||||
(SELECT * FROM ft4 WHERE EXISTS (
|
||||
SELECT 1 FROM ft2 WHERE ft2.c2 = ft4.c2)) ft4
|
||||
ON ft2.c2 = ft4.c1
|
||||
INNER JOIN
|
||||
(SELECT * FROM ft2 WHERE EXISTS (
|
||||
SELECT 1 FROM ft4 WHERE ft2.c2 = ft4.c2)) ft21
|
||||
ON ft2.c2 = ft21.c2
|
||||
WHERE ft2.c1 > 900
|
||||
ORDER BY ft2.c1 LIMIT 10;
|
||||
QUERY PLAN
|
||||
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
||||
Foreign Scan
|
||||
Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3
|
||||
Relations: ((((public.ft2) INNER JOIN (public.ft4)) SEMI JOIN (public.ft2 ft2_1)) INNER JOIN (public.ft2 ft2_2)) SEMI JOIN (public.ft4 ft4_1)
|
||||
Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, r6.c1, r6.c2, r6.c3 FROM (("S 1"."T 1" r1 INNER JOIN "S 1"."T 3" r6 ON (((r1.c2 = r6.c1)) AND ((r1."C 1" > 900)))) INNER JOIN "S 1"."T 1" r8 ON (((r1.c2 = r8.c2)))) WHERE EXISTS (SELECT NULL FROM "S 1"."T 3" r9 WHERE ((r1.c2 = r9.c2))) AND EXISTS (SELECT NULL FROM "S 1"."T 1" r7 WHERE ((r7.c2 = r6.c2))) ORDER BY r1."C 1" ASC NULLS LAST LIMIT 10::bigint
|
||||
(4 rows)
|
||||
|
||||
SELECT ft2.*, ft4.* FROM ft2 INNER JOIN
|
||||
(SELECT * FROM ft4 WHERE EXISTS (
|
||||
SELECT 1 FROM ft2 WHERE ft2.c2 = ft4.c2)) ft4
|
||||
ON ft2.c2 = ft4.c1
|
||||
INNER JOIN
|
||||
(SELECT * FROM ft2 WHERE EXISTS (
|
||||
SELECT 1 FROM ft4 WHERE ft2.c2 = ft4.c2)) ft21
|
||||
ON ft2.c2 = ft21.c2
|
||||
WHERE ft2.c1 > 900
|
||||
ORDER BY ft2.c1 LIMIT 10;
|
||||
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3
|
||||
----+----+----+----+----+----+----+----+----+----+----
|
||||
(0 rows)
|
||||
|
||||
-- Can't push down semi-join with inner rel vars in targetlist
|
||||
EXPLAIN (verbose, costs off)
|
||||
SELECT ft1.c1 FROM ft1 JOIN ft2 on ft1.c1 = ft2.c1 WHERE
|
||||
ft1.c1 IN (
|
||||
SELECT ft2.c1 FROM ft2 JOIN ft4 ON ft2.c1 = ft4.c1)
|
||||
ORDER BY ft1.c1 LIMIT 5;
|
||||
QUERY PLAN
|
||||
-------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
||||
Limit
|
||||
Output: ft1.c1
|
||||
-> Merge Semi Join
|
||||
Output: ft1.c1
|
||||
Merge Cond: (ft1.c1 = ft2_1.c1)
|
||||
-> Foreign Scan
|
||||
Output: ft1.c1, ft2.c1
|
||||
Relations: (public.ft1) INNER JOIN (public.ft2)
|
||||
Remote SQL: SELECT r1."C 1", r2."C 1" FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r1."C 1")))) ORDER BY r1."C 1" ASC NULLS LAST
|
||||
-> Foreign Scan
|
||||
Output: ft2_1.c1, ft4.c1
|
||||
Relations: (public.ft2 ft2_1) INNER JOIN (public.ft4)
|
||||
Remote SQL: SELECT r5."C 1", r6.c1 FROM ("S 1"."T 1" r5 INNER JOIN "S 1"."T 3" r6 ON (((r5."C 1" = r6.c1)))) ORDER BY r5."C 1" ASC NULLS LAST
|
||||
(13 rows)
|
||||
|
||||
-- ===================================================================
|
||||
-- test writable foreign table stuff
|
||||
-- ===================================================================
|
||||
|
||||
Reference in New Issue
Block a user