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postgres_fdw: Perform the (FINAL, NULL) upperrel operations remotely.

Browse Source 
The upper-planner pathification allows FDWs to arrange to push down
different types of upper-stage operations to the remote side.  This
commit teaches postgres_fdw to do it for the (FINAL, NULL) upperrel,
which is responsible for doing LockRows, LIMIT, and/or ModifyTable.
This provides the ability for postgres_fdw to handle SELECT commands
so that it 1) skips the LockRows step (if any) (note that this is
safe since it performs early locking) and 2) pushes down the LIMIT
and/or OFFSET restrictions (if any) to the remote side.  This doesn't
handle the INSERT/UPDATE/DELETE cases.

Author: Etsuro Fujita
Reviewed-By: Antonin Houska and Jeff Janes
Discussion: https://postgr.es/m/87pnz1aby9.fsf@news-spur.riddles.org.uk
pull/40/head
Etsuro Fujita 7 years ago
parent aef65db676
commit d50d172e51
7 changed files with 656 additions and 390 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 37
      contrib/postgres_fdw/deparse.c
  2. 620
      contrib/postgres_fdw/expected/postgres_fdw.out
  3. 342
      contrib/postgres_fdw/postgres_fdw.c
  4. 3
      contrib/postgres_fdw/postgres_fdw.h
  5. 16
      contrib/postgres_fdw/sql/postgres_fdw.sql
  6. 10
      src/backend/optimizer/plan/planner.c
  7. 18
      src/include/nodes/pathnodes.h

37
contrib/postgres_fdw/deparse.c
Unescape View File

@ -169,6 +169,7 @@ static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_att
static void deparseLockingClause(deparse_expr_cxt *context);
static void appendOrderByClause(List *pathkeys, bool has_final_sort,
deparse_expr_cxt *context);
static void appendLimitClause(deparse_expr_cxt *context);
static void appendConditions(List *exprs, deparse_expr_cxt *context);
static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
RelOptInfo *foreignrel, bool use_alias,
@ -930,7 +931,7 @@ build_tlist_to_deparse(RelOptInfo *foreignrel)
void
deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
List *tlist, List *remote_conds, List *pathkeys,
bool has_final_sort, bool is_subquery,
bool has_final_sort, bool has_limit, bool is_subquery,
List **retrieved_attrs, List **params_list)
{
deparse_expr_cxt context;
@ -988,6 +989,10 @@ deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
if (pathkeys)
appendOrderByClause(pathkeys, has_final_sort, &context);
/* Add LIMIT clause if necessary */
if (has_limit)
appendLimitClause(&context);
/* Add any necessary FOR UPDATE/SHARE. */
deparseLockingClause(&context);
}
@ -1591,7 +1596,8 @@ deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
/* Deparse the subquery representing the relation. */
appendStringInfoChar(buf, '(');
deparseSelectStmtForRel(buf, root, foreignrel, NIL,
fpinfo->remote_conds, NIL, false, true,
fpinfo->remote_conds, NIL,
false, false, true,
&retrieved_attrs, params_list);
appendStringInfoChar(buf, ')');
@ -3160,6 +3166,33 @@ appendOrderByClause(List *pathkeys, bool has_final_sort,
reset_transmission_modes(nestlevel);
}
/*
* Deparse LIMIT/OFFSET clause.
*/
static void
appendLimitClause(deparse_expr_cxt *context)
{
PlannerInfo *root = context->root;
StringInfo buf = context->buf;
int nestlevel;
/* Make sure any constants in the exprs are printed portably */
nestlevel = set_transmission_modes();
if (root->parse->limitCount)
{
appendStringInfoString(buf, " LIMIT ");
deparseExpr((Expr *) root->parse->limitCount, context);
}
if (root->parse->limitOffset)
{
appendStringInfoString(buf, " OFFSET ");
deparseExpr((Expr *) root->parse->limitOffset, context);
}
reset_transmission_modes(nestlevel);
}
/*
* appendFunctionName
* Deparses function name from given function oid.

620
contrib/postgres_fdw/expected/postgres_fdw.out
Unescape View File

@ -236,11 +236,10 @@ ALTER FOREIGN TABLE ft2 OPTIONS (use_remote_estimate 'true');
-- ===================================================================
-- single table without alias
EXPLAIN (COSTS OFF) SELECT * FROM ft1 ORDER BY c3, c1 OFFSET 100 LIMIT 10;
QUERY PLAN
---------------------------
Limit
-> Foreign Scan on ft1
(2 rows)
QUERY PLAN
---------------------
Foreign Scan on ft1
(1 row)
SELECT * FROM ft1 ORDER BY c3, c1 OFFSET 100 LIMIT 10;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -288,14 +287,12 @@ SELECT * FROM ft1 t1 ORDER BY t1.c3, t1.c1, t1.tableoid OFFSET 100 LIMIT 10;
-- whole-row reference
EXPLAIN (VERBOSE, COSTS OFF) SELECT t1 FROM ft1 t1 ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1 t1
Output: t1.*, c3, c1
-> Foreign Scan on public.ft1 t1
Output: t1.*, c3, c1
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c3 ASC NULLS LAST, "C 1" ASC NULLS LAST
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c3 ASC NULLS LAST, "C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint
(3 rows)
SELECT t1 FROM ft1 t1 ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
t1
@ -335,14 +332,12 @@ SELECT * FROM ft1 t1 WHERE t1.c1 = 101 AND t1.c6 = '1' AND t1.c7 >= '1';
-- with FOR UPDATE/SHARE
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------
LockRows
QUERY PLAN
----------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1 t1
Output: c1, c2, c3, c4, c5, c6, c7, c8, t1.*
-> Foreign Scan on public.ft1 t1
Output: c1, c2, c3, c4, c5, c6, c7, c8, t1.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" = 101)) FOR UPDATE
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" = 101)) FOR UPDATE
(3 rows)
SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -351,14 +346,12 @@ SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE;
(1 row)
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE;
QUERY PLAN
---------------------------------------------------------------------------------------------------------------
LockRows
QUERY PLAN
---------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1 t1
Output: c1, c2, c3, c4, c5, c6, c7, c8, t1.*
-> Foreign Scan on public.ft1 t1
Output: c1, c2, c3, c4, c5, c6, c7, c8, t1.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" = 102)) FOR SHARE
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" = 102)) FOR SHARE
(3 rows)
SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -968,6 +961,25 @@ SELECT count(c3) FROM ft1 t1 WHERE t1.c1 === t1.c2;
9
(1 row)
-- ORDER BY can be shipped, though
EXPLAIN (VERBOSE, COSTS OFF)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
QUERY PLAN
----------------------------------------------------------------------------------------------------------
Limit
Output: c1, c2, c3, c4, c5, c6, c7, c8
-> Foreign Scan on public.ft1 t1
Output: c1, c2, c3, c4, c5, c6, c7, c8
Filter: (t1.c1 === t1.c2)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c2 ASC NULLS LAST
(6 rows)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
----+----+-------+------------------------------+--------------------------+----+------------+-----
1 | 1 | 00001 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
(1 row)
-- but let's put them in an extension ...
ALTER EXTENSION postgres_fdw ADD FUNCTION postgres_fdw_abs(int);
ALTER EXTENSION postgres_fdw ADD OPERATOR === (int, int);
@ -1005,6 +1017,22 @@ SELECT count(c3) FROM ft1 t1 WHERE t1.c1 === t1.c2;
9
(1 row)
-- and both ORDER BY and LIMIT can be shipped
EXPLAIN (VERBOSE, COSTS OFF)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1 t1
Output: c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" OPERATOR(public.===) c2)) ORDER BY c2 ASC NULLS LAST LIMIT 1::bigint
(3 rows)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
----+----+-------+------------------------------+--------------------------+----+------------+-----
1 | 1 | 00001 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
(1 row)
-- ===================================================================
-- JOIN queries
-- ===================================================================
@ -1015,15 +1043,13 @@ ANALYZE ft5;
-- join two tables
EXPLAIN (VERBOSE, COSTS OFF)
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;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1, t1.c3
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST
(6 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint
(4 rows)
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;
c1 | c1
@ -1043,18 +1069,13 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-- join three tables
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) JOIN ft4 t3 ON (t3.c1 = t1.c1) ORDER BY t1.c3, t1.c1 OFFSET 10 LIMIT 10;
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3, t1.c3
-> Sort
Output: t1.c1, t2.c2, t3.c3, t1.c3
Sort Key: t1.c3, t1.c1
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3, t1.c3
Relations: ((public.ft1 t1) INNER JOIN (public.ft2 t2)) INNER JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3, r1.c3 FROM (("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) INNER JOIN "S 1"."T 3" r4 ON (((r1."C 1" = r4.c1))))
(9 rows)
Relations: ((public.ft1 t1) INNER JOIN (public.ft2 t2)) INNER JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3, r1.c3 FROM (("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) INNER JOIN "S 1"."T 3" r4 ON (((r1."C 1" = r4.c1)))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) JOIN ft4 t3 ON (t3.c1 = t1.c1) ORDER BY t1.c3, t1.c1 OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1074,15 +1095,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) JOIN ft4 t
-- left outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1
-> Foreign Scan
Output: t1.c1, t2.c1
Relations: (public.ft4 t1) LEFT JOIN (public.ft5 t2)
Remote SQL: SELECT r1.c1, r2.c1 FROM ("S 1"."T 3" r1 LEFT JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) ORDER BY r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST
(6 rows)
Relations: (public.ft4 t1) LEFT JOIN (public.ft5 t2)
Remote SQL: SELECT r1.c1, r2.c1 FROM ("S 1"."T 3" r1 LEFT JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) ORDER BY r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c1 FROM ft4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
c1 | c1
@ -1102,15 +1121,13 @@ SELECT t1.c1, t2.c1 FROM ft4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.
-- left outer join three tables
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 LEFT JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: ((public.ft2 t1) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 LEFT JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1175,15 +1192,13 @@ SELECT t1.c1, t1.c2, t2.c1, t2.c2 FROM ft4 t1 LEFT JOIN (SELECT * FROM ft5 WHERE
-- right outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft5 t1 RIGHT JOIN ft4 t2 ON (t1.c1 = t2.c1) ORDER BY t2.c1, t1.c1 OFFSET 10 LIMIT 10;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1
-> Foreign Scan
Output: t1.c1, t2.c1
Relations: (public.ft4 t2) LEFT JOIN (public.ft5 t1)
Remote SQL: SELECT r1.c1, r2.c1 FROM ("S 1"."T 3" r2 LEFT JOIN "S 1"."T 4" r1 ON (((r1.c1 = r2.c1)))) ORDER BY r2.c1 ASC NULLS LAST, r1.c1 ASC NULLS LAST
(6 rows)
Relations: (public.ft4 t2) LEFT JOIN (public.ft5 t1)
Remote SQL: SELECT r1.c1, r2.c1 FROM ("S 1"."T 3" r2 LEFT JOIN "S 1"."T 4" r1 ON (((r1.c1 = r2.c1)))) ORDER BY r2.c1 ASC NULLS LAST, r1.c1 ASC NULLS LAST LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c1 FROM ft5 t1 RIGHT JOIN ft4 t2 ON (t1.c1 = t2.c1) ORDER BY t2.c1, t1.c1 OFFSET 10 LIMIT 10;
c1 | c1
@ -1203,15 +1218,13 @@ SELECT t1.c1, t2.c1 FROM ft5 t1 RIGHT JOIN ft4 t2 ON (t1.c1 = t2.c1) ORDER BY t2
-- right outer join three tables
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft4 t3) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft2 t1)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 3" r4 LEFT JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r4.c1)))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1"))))
(6 rows)
Relations: ((public.ft4 t3) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft2 t1)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 3" r4 LEFT JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r4.c1)))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1231,15 +1244,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGH
-- full outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1
-> Foreign Scan
Output: t1.c1, t2.c1
Relations: (public.ft4 t1) FULL JOIN (public.ft5 t2)
Remote SQL: SELECT r1.c1, r2.c1 FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) ORDER BY r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST
(6 rows)
Relations: (public.ft4 t1) FULL JOIN (public.ft5 t2)
Remote SQL: SELECT r1.c1, r2.c1 FROM ("S 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) ORDER BY r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST LIMIT 10::bigint OFFSET 45::bigint
(4 rows)
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
c1 | c1
@ -1283,15 +1294,13 @@ SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL
EXPLAIN (VERBOSE, COSTS OFF)
SELECT 1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (TRUE) OFFSET 10 LIMIT 10;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: 1
-> Foreign Scan
Output: 1
Relations: (public.ft4) FULL JOIN (public.ft5)
Remote SQL: SELECT NULL FROM ((SELECT NULL FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s4 FULL JOIN (SELECT NULL FROM "S 1"."T 4" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s5 ON (TRUE))
(6 rows)
Relations: (public.ft4) FULL JOIN (public.ft5)
Remote SQL: SELECT NULL FROM ((SELECT NULL FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s4 FULL JOIN (SELECT NULL FROM "S 1"."T 4" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s5 ON (TRUE)) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT 1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (TRUE) OFFSET 10 LIMIT 10;
?column?
@ -1406,15 +1415,13 @@ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM "S 1"."T 3" WHERE c1 = 50) t1 INNE
-- full outer join + inner join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1, t3.c1 FROM ft4 t1 INNER JOIN ft5 t2 ON (t1.c1 = t2.c1 + 1 and t1.c1 between 50 and 60) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) ORDER BY t1.c1, t2.c1, t3.c1 LIMIT 10;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1, t3.c1
-> Foreign Scan
Output: t1.c1, t2.c1, t3.c1
Relations: ((public.ft4 t1) INNER JOIN (public.ft5 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1.c1, r2.c1, r4.c1 FROM (("S 1"."T 3" r1 INNER JOIN "S 1"."T 4" r2 ON (((r1.c1 = (r2.c1 + 1))) AND ((r1.c1 >= 50)) AND ((r1.c1 <= 60)))) FULL JOIN "S 1"."T 3" r4 ON (((r2.c1 = r4.c1)))) ORDER BY r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST, r4.c1 ASC NULLS LAST
(6 rows)
Relations: ((public.ft4 t1) INNER JOIN (public.ft5 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1.c1, r2.c1, r4.c1 FROM (("S 1"."T 3" r1 INNER JOIN "S 1"."T 4" r2 ON (((r1.c1 = (r2.c1 + 1))) AND ((r1.c1 >= 50)) AND ((r1.c1 <= 60)))) FULL JOIN "S 1"."T 3" r4 ON (((r2.c1 = r4.c1)))) ORDER BY r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST, r4.c1 ASC NULLS LAST LIMIT 10::bigint
(4 rows)
SELECT t1.c1, t2.c1, t3.c1 FROM ft4 t1 INNER JOIN ft5 t2 ON (t1.c1 = t2.c1 + 1 and t1.c1 between 50 and 60) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) ORDER BY t1.c1, t2.c1, t3.c1 LIMIT 10;
c1 | c1 | c1
@ -1434,15 +1441,13 @@ SELECT t1.c1, t2.c1, t3.c1 FROM ft4 t1 INNER JOIN ft5 t2 ON (t1.c1 = t2.c1 + 1 a
-- full outer join three tables
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) FULL JOIN (public.ft2 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: ((public.ft2 t1) FULL JOIN (public.ft2 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1462,15 +1467,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL
-- full outer join + right outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft4 t3) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft2 t1)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 3" r4 LEFT JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r4.c1)))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1"))))
(6 rows)
Relations: ((public.ft4 t3) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft2 t1)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 3" r4 LEFT JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r4.c1)))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1490,15 +1493,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT
-- right outer join + full outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t2) LEFT JOIN (public.ft2 t1)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r2 LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: ((public.ft2 t2) LEFT JOIN (public.ft2 t1)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r2 LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1518,15 +1519,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL
-- full outer join + left outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) FULL JOIN (public.ft2 t2)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: ((public.ft2 t1) FULL JOIN (public.ft2 t2)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1546,15 +1545,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT
-- left outer join + full outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) LEFT JOIN (public.ft2 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 LEFT JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: ((public.ft2 t1) LEFT JOIN (public.ft2 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 LEFT JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1574,15 +1571,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL
-- right outer join + left outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t2) LEFT JOIN (public.ft2 t1)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r2 LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: ((public.ft2 t2) LEFT JOIN (public.ft2 t1)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r2 LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1602,15 +1597,13 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT
-- left outer join + right outer join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: (public.ft4 t3) LEFT JOIN ((public.ft2 t1) INNER JOIN (public.ft2 t2))
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM ("S 1"."T 3" r4 LEFT JOIN ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ON (((r2."C 1" = r4.c1))))
(6 rows)
Relations: (public.ft4 t3) LEFT JOIN ((public.ft2 t1) INNER JOIN (public.ft2 t2))
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM ("S 1"."T 3" r4 LEFT JOIN ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ON (((r2."C 1" = r4.c1)))) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
@ -1661,15 +1654,13 @@ SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) WHERE (t1.c1
-- full outer join + WHERE clause with shippable extensions set
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2, t1.c3 FROM ft1 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) WHERE postgres_fdw_abs(t1.c1) > 0 OFFSET 10 LIMIT 10;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c2, t1.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t1.c3
Relations: (public.ft1 t1) FULL JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2.c2, r1.c3 FROM ("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) WHERE ((public.postgres_fdw_abs(r1."C 1") > 0))
(6 rows)
Relations: (public.ft1 t1) FULL JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2.c2, r1.c3 FROM ("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) WHERE ((public.postgres_fdw_abs(r1."C 1") > 0)) LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
ALTER SERVER loopback OPTIONS (DROP extensions);
-- full outer join + WHERE clause with shippable extensions not set
@ -1691,37 +1682,13 @@ ALTER SERVER loopback OPTIONS (ADD extensions 'postgres_fdw');
-- tests whole-row reference for row marks
EXPLAIN (VERBOSE, COSTS OFF)
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 UPDATE OF t1;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR UPDATE OF r1
-> Result
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Sort
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Sort Key: t1.c3, t1.c1
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
-> Sort
Output: t1.c1, t1.c3, t1.*
Sort Key: t1.c1
-> Foreign Scan on public.ft1 t1
Output: t1.c1, t1.c3, t1.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR UPDATE
-> Sort
Output: t2.c1, t2.*
Sort Key: t2.c1
-> Foreign Scan on public.ft2 t2
Output: t2.c1, t2.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1"
(28 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR UPDATE OF r1
(4 rows)
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 UPDATE OF t1;
c1 | c1
@ -1740,37 +1707,13 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
EXPLAIN (VERBOSE, COSTS OFF)
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 UPDATE;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR UPDATE OF r1 FOR UPDATE OF r2
-> Result
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Sort
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Sort Key: t1.c3, t1.c1
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
-> Sort
Output: t1.c1, t1.c3, t1.*
Sort Key: t1.c1
-> Foreign Scan on public.ft1 t1
Output: t1.c1, t1.c3, t1.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR UPDATE
-> Sort
Output: t2.c1, t2.*
Sort Key: t2.c1
-> Foreign Scan on public.ft2 t2
Output: t2.c1, t2.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR UPDATE
(28 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR UPDATE OF r1 FOR UPDATE OF r2
(4 rows)
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 UPDATE;
c1 | c1
@ -1790,37 +1733,13 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-- join two tables with FOR SHARE clause
EXPLAIN (VERBOSE, COSTS OFF)
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 OF t1;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR SHARE OF r1
-> Result
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Sort
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Sort Key: t1.c3, t1.c1
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
-> Sort
Output: t1.c1, t1.c3, t1.*
Sort Key: t1.c1
-> Foreign Scan on public.ft1 t1
Output: t1.c1, t1.c3, t1.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR SHARE
-> Sort
Output: t2.c1, t2.*
Sort Key: t2.c1
-> Foreign Scan on public.ft2 t2
Output: t2.c1, t2.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1"
(28 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR SHARE OF r1
(4 rows)
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 OF t1;
c1 | c1
@ -1839,37 +1758,13 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
EXPLAIN (VERBOSE, COSTS OFF)
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;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR SHARE OF r1 FOR SHARE OF r2
-> Result
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> Sort
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Sort Key: t1.c3, t1.c1
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
-> Sort
Output: t1.c1, t1.c3, t1.*
Sort Key: t1.c1
-> Foreign Scan on public.ft1 t1
Output: t1.c1, t1.c3, t1.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR SHARE
-> Sort
Output: t2.c1, t2.*
Sort Key: t2.c1
-> Foreign Scan on public.ft2 t2
Output: t2.c1, t2.*
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR SHARE
(28 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, 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 FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR SHARE OF r1 FOR SHARE OF r2
(4 rows)
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;
c1 | c1
@ -1923,15 +1818,13 @@ WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t
-- 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;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.ctid, t1.*, t2.*, t1.c1, t1.c3
-> Foreign Scan
Output: t1.ctid, t1.*, t2.*, t1.c1, t1.c3
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
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 (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST
(6 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
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 (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint
(4 rows)
-- SEMI JOIN, not pushed down
EXPLAIN (VERBOSE, COSTS OFF)
@ -1999,27 +1892,16 @@ SELECT t1.c1 FROM ft1 t1 WHERE NOT EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2
119
(10 rows)
-- CROSS JOIN, not pushed down
-- CROSS JOIN can be pushed down
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
QUERY PLAN
---------------------------------------------------------------------
Limit
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: t1.c1, t2.c1
-> Sort
Output: t1.c1, t2.c1
Sort Key: t1.c1, t2.c1
-> Nested Loop
Output: t1.c1, t2.c1
-> Foreign Scan on public.ft1 t1
Output: t1.c1
Remote SQL: SELECT "C 1" FROM "S 1"."T 1"
-> Materialize
Output: t2.c1
-> Foreign Scan on public.ft2 t2
Output: t2.c1
Remote SQL: SELECT "C 1" FROM "S 1"."T 1"
(15 rows)
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
Remote SQL: SELECT r1."C 1", r2."C 1" FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (TRUE)) ORDER BY r1."C 1" ASC NULLS LAST, r2."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint
(4 rows)
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
c1 | c1
@ -2462,15 +2344,13 @@ SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN v5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1
ALTER VIEW v4 OWNER TO regress_view_owner;
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN v5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10; -- can be pushed down
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: ft4.c1, ft5.c2, ft5.c1
-> Foreign Scan
Output: ft4.c1, ft5.c2, ft5.c1
Relations: (public.ft4) LEFT JOIN (public.ft5)
Remote SQL: SELECT r6.c1, r9.c2, r9.c1 FROM ("S 1"."T 3" r6 LEFT JOIN "S 1"."T 4" r9 ON (((r6.c1 = r9.c1)))) ORDER BY r6.c1 ASC NULLS LAST, r9.c1 ASC NULLS LAST
(6 rows)
Relations: (public.ft4) LEFT JOIN (public.ft5)
Remote SQL: SELECT r6.c1, r9.c2, r9.c1 FROM ("S 1"."T 3" r6 LEFT JOIN "S 1"."T 4" r9 ON (((r6.c1 = r9.c1)))) ORDER BY r6.c1 ASC NULLS LAST, r9.c1 ASC NULLS LAST LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN v5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
c1 | c2
@ -2527,15 +2407,13 @@ SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c
ALTER VIEW v4 OWNER TO CURRENT_USER;
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10; -- can be pushed down
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: ft4.c1, t2.c2, t2.c1
-> Foreign Scan
Output: ft4.c1, t2.c2, t2.c1
Relations: (public.ft4) LEFT JOIN (public.ft5 t2)
Remote SQL: SELECT r6.c1, r2.c2, r2.c1 FROM ("S 1"."T 3" r6 LEFT JOIN "S 1"."T 4" r2 ON (((r6.c1 = r2.c1)))) ORDER BY r6.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST
(6 rows)
Relations: (public.ft4) LEFT JOIN (public.ft5 t2)
Remote SQL: SELECT r6.c1, r2.c2, r2.c1 FROM ("S 1"."T 3" r6 LEFT JOIN "S 1"."T 4" r2 ON (((r6.c1 = r2.c1)))) ORDER BY r6.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST LIMIT 10::bigint OFFSET 10::bigint
(4 rows)
SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
c1 | c2
@ -2580,6 +2458,22 @@ select count(c6), sum(c1), avg(c1), min(c2), max(c1), stddev(c2), sum(c1) * (ran
100 | 50500 | 505.0000000000000000 | 0 | 1000 | 0 | 50500
(5 rows)
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 limit 1;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: (count(c6)), (sum(c1)), (avg(c1)), (min(c2)), (max(c1)), (stddev(c2)), ((sum(c1)) * ((random() <= '1'::double precision))::integer), 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 7 ORDER BY count(c6) ASC NULLS LAST, sum("C 1") ASC NULLS LAST LIMIT 1::bigint
(4 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 limit 1;
count | sum | avg | min | max | stddev | sum2
-------+-------+----------------------+-----+-----+--------+-------
100 | 49600 | 496.0000000000000000 | 1 | 991 | 0 | 49600
(1 row)
-- Aggregate is not pushed down as aggregation contains random()
explain (verbose, costs off)
select sum(c1 * (random() <= 1)::int) as sum, avg(c1) from ft1;
@ -4034,14 +3928,12 @@ SELECT * FROM ft1 t1 WHERE t1.tableoid = 'ft1'::regclass LIMIT 1;
EXPLAIN (VERBOSE, COSTS OFF)
SELECT tableoid::regclass, * FROM ft1 t1 LIMIT 1;
QUERY PLAN
-------------------------------------------------------------------------------
Limit
Output: ((tableoid)::regclass), c1, c2, c3, c4, c5, c6, c7, c8
-> Foreign Scan on public.ft1 t1
Output: (tableoid)::regclass, c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1"
(5 rows)
QUERY PLAN
-----------------------------------------------------------------------------------------
Foreign Scan on public.ft1 t1
Output: (tableoid)::regclass, c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" LIMIT 1::bigint
(3 rows)
SELECT tableoid::regclass, * FROM ft1 t1 LIMIT 1;
tableoid | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -4066,14 +3958,12 @@ SELECT * FROM ft1 t1 WHERE t1.ctid = '(0,2)';
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ctid, * FROM ft1 t1 LIMIT 1;
QUERY PLAN
-------------------------------------------------------------------------------------
Limit
QUERY PLAN
-----------------------------------------------------------------------------------------------
Foreign Scan on public.ft1 t1
Output: ctid, c1, c2, c3, c4, c5, c6, c7, c8
-> Foreign Scan on public.ft1 t1
Output: ctid, c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8, ctid FROM "S 1"."T 1"
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8, ctid FROM "S 1"."T 1" LIMIT 1::bigint
(3 rows)
SELECT ctid, * FROM ft1 t1 LIMIT 1;
ctid | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -4278,12 +4168,10 @@ INSERT INTO ft2 (c1,c2,c3) SELECT c1+1000,c2+100, c3 || c3 FROM ft2 LIMIT 20;
Remote SQL: INSERT INTO "S 1"."T 1"("C 1", c2, c3, c4, c5, c6, c7, c8) VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
-> Subquery Scan on "*SELECT*"
Output: "*SELECT*"."?column?", "*SELECT*"."?column?_1", NULL::integer, "*SELECT*"."?column?_2", NULL::timestamp with time zone, NULL::timestamp without time zone, NULL::character varying, 'ft2 '::character(10), NULL::user_enum
-> Limit
Output: ((ft2_1.c1 + 1000)), ((ft2_1.c2 + 100)), ((ft2_1.c3 || ft2_1.c3))
-> Foreign Scan on public.ft2 ft2_1
Output: (ft2_1.c1 + 1000), (ft2_1.c2 + 100), (ft2_1.c3 || ft2_1.c3)
Remote SQL: SELECT "C 1", c2, c3 FROM "S 1"."T 1"
(9 rows)
-> Foreign Scan on public.ft2 ft2_1
Output: (ft2_1.c1 + 1000), (ft2_1.c2 + 100), (ft2_1.c3 || ft2_1.c3)
Remote SQL: SELECT "C 1", c2, c3 FROM "S 1"."T 1" LIMIT 20::bigint
(7 rows)
INSERT INTO ft2 (c1,c2,c3) SELECT c1+1000,c2+100, c3 || c3 FROM ft2 LIMIT 20;
INSERT INTO ft2 (c1,c2,c3)
@ -6030,14 +5918,12 @@ VACUUM ANALYZE "S 1"."T 1";
-- FIRST behavior here.
-- ORDER BY DESC NULLS LAST options
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 ORDER BY c6 DESC NULLS LAST, c1 OFFSET 795 LIMIT 10;
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1
Output: c1, c2, c3, c4, c5, c6, c7, c8
-> Foreign Scan on public.ft1
Output: c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c6 DESC NULLS LAST, "C 1" ASC NULLS LAST
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c6 DESC NULLS LAST, "C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 795::bigint
(3 rows)
SELECT * FROM ft1 ORDER BY c6 DESC NULLS LAST, c1 OFFSET 795 LIMIT 10;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -6056,14 +5942,12 @@ SELECT * FROM ft1 ORDER BY c6 DESC NULLS LAST, c1 OFFSET 795 LIMIT 10;
-- ORDER BY DESC NULLS FIRST options
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 ORDER BY c6 DESC NULLS FIRST, c1 OFFSET 15 LIMIT 10;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1
Output: c1, c2, c3, c4, c5, c6, c7, c8
-> Foreign Scan on public.ft1
Output: c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c6 DESC NULLS FIRST, "C 1" ASC NULLS LAST
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c6 DESC NULLS FIRST, "C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 15::bigint
(3 rows)
SELECT * FROM ft1 ORDER BY c6 DESC NULLS FIRST, c1 OFFSET 15 LIMIT 10;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
@ -6082,14 +5966,12 @@ SELECT * FROM ft1 ORDER BY c6 DESC NULLS FIRST, c1 OFFSET 15 LIMIT 10;
-- ORDER BY ASC NULLS FIRST options
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 ORDER BY c6 ASC NULLS FIRST, c1 OFFSET 15 LIMIT 10;
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------
Limit
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan on public.ft1
Output: c1, c2, c3, c4, c5, c6, c7, c8
-> Foreign Scan on public.ft1
Output: c1, c2, c3, c4, c5, c6, c7, c8
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c6 ASC NULLS FIRST, "C 1" ASC NULLS LAST
(5 rows)
Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" ORDER BY c6 ASC NULLS FIRST, "C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 15::bigint
(3 rows)
SELECT * FROM ft1 ORDER BY c6 ASC NULLS FIRST, c1 OFFSET 15 LIMIT 10;
c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8

342
contrib/postgres_fdw/postgres_fdw.c
Unescape View File

@ -251,11 +251,14 @@ typedef struct PgFdwAnalyzeState
* We store:
*
* 1) Boolean flag showing if the remote query has the final sort
* 2) Boolean flag showing if the remote query has the LIMIT clause
*/
enum FdwPathPrivateIndex
{
/* has-final-sort flag (as an integer Value node) */
FdwPathPrivateHasFinalSort
FdwPathPrivateHasFinalSort,
/* has-limit flag (as an integer Value node) */
FdwPathPrivateHasLimit
};
/* Struct for extra information passed to estimate_path_cost_size() */
@ -263,6 +266,10 @@ typedef struct
{
PathTarget *target;
bool has_final_sort;
bool has_limit;
double limit_tuples;
int64 count_est;
int64 offset_est;
} PgFdwPathExtraData;
/*
@ -400,6 +407,7 @@ static void adjust_foreign_grouping_path_cost(PlannerInfo *root,
List *pathkeys,
double retrieved_rows,
double width,
double limit_tuples,
Cost *p_startup_cost,
Cost *p_run_cost);
static bool ec_member_matches_foreign(PlannerInfo *root, RelOptInfo *rel,
@ -481,6 +489,10 @@ static void add_foreign_grouping_paths(PlannerInfo *root,
static void add_foreign_ordered_paths(PlannerInfo *root,
RelOptInfo *input_rel,
RelOptInfo *ordered_rel);
static void add_foreign_final_paths(PlannerInfo *root,
RelOptInfo *input_rel,
RelOptInfo *final_rel,
FinalPathExtraData *extra);
static void apply_server_options(PgFdwRelationInfo *fpinfo);
static void apply_table_options(PgFdwRelationInfo *fpinfo);
static void merge_fdw_options(PgFdwRelationInfo *fpinfo,
@ -1183,14 +1195,19 @@ postgresGetForeignPlan(PlannerInfo *root,
List *retrieved_attrs;
StringInfoData sql;
bool has_final_sort = false;
bool has_limit = false;
ListCell *lc;
/*
* Get FDW private data created by postgresGetForeignUpperPaths(), if any.
*/
if (best_path->fdw_private)
{
has_final_sort = intVal(list_nth(best_path->fdw_private,
FdwPathPrivateHasFinalSort));
has_limit = intVal(list_nth(best_path->fdw_private,
FdwPathPrivateHasLimit));
}
if (IS_SIMPLE_REL(foreignrel))
{
@ -1340,7 +1357,7 @@ postgresGetForeignPlan(PlannerInfo *root,
initStringInfo(&sql);
deparseSelectStmtForRel(&sql, root, foreignrel, fdw_scan_tlist,
remote_exprs, best_path->path.pathkeys,
has_final_sort, false,
has_final_sort, has_limit, false,
&retrieved_attrs, &params_list);
/* Remember remote_exprs for possible use by postgresPlanDirectModify */
@ -2526,7 +2543,7 @@ postgresExplainDirectModify(ForeignScanState *node, ExplainState *es)
* param_join_conds are the parameterization clauses with outer relations.
* pathkeys specify the expected sort order if any for given path being costed.
* fpextra specifies additional post-scan/join-processing steps such as the
* final sort.
* final sort and the LIMIT restriction.
*
* The function returns the cost and size estimates in p_row, p_width,
* p_startup_cost and p_total_cost variables.
@ -2603,6 +2620,7 @@ estimate_path_cost_size(PlannerInfo *root,
deparseSelectStmtForRel(&sql, root, foreignrel, fdw_scan_tlist,
remote_conds, pathkeys,
fpextra ? fpextra->has_final_sort : false,
fpextra ? fpextra->has_limit : false,
false, &retrieved_attrs, NULL);
/* Get the remote estimate */
@ -2670,15 +2688,34 @@ estimate_path_cost_size(PlannerInfo *root,
retrieved_rows = clamp_row_est(rows / fpinfo->local_conds_sel);
/*
* We will come here again and again with different set of pathkeys
* that caller wants to cost. We don't need to calculate the costs of
* the underlying scan, join, or grouping each time. Instead, use the
* costs if we have cached them already.
* We will come here again and again with different set of pathkeys or
* additional post-scan/join-processing steps that caller wants to
* cost. We don't need to calculate the costs of the underlying scan,
* join, or grouping each time. Instead, use the costs if we have
* cached them already.
*/
if (fpinfo->rel_startup_cost >= 0 && fpinfo->rel_total_cost >= 0)
{
startup_cost = fpinfo->rel_startup_cost;
run_cost = fpinfo->rel_total_cost - fpinfo->rel_startup_cost;
/*
* If we estimate the costs of a foreign scan or a foreign join
* with additional post-scan/join-processing steps, the scan or
* join costs obtained from the cache wouldn't yet contain the
* eval costs for the final scan/join target, which would've been
* updated by apply_scanjoin_target_to_paths(); add the eval costs
* now.
*/
if (fpextra && !IS_UPPER_REL(foreignrel))
{
/* Shouldn't get here unless we have LIMIT */
Assert(fpextra->has_limit);
Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
foreignrel->reloptkind == RELOPT_JOINREL);
startup_cost += foreignrel->reltarget->cost.startup;
run_cost += foreignrel->reltarget->cost.per_tuple * rows;
}
}
else if (IS_JOIN_REL(foreignrel))
{
@ -2897,6 +2934,7 @@ estimate_path_cost_size(PlannerInfo *root,
fpinfo->stage == UPPERREL_GROUP_AGG);
adjust_foreign_grouping_path_cost(root, pathkeys,
retrieved_rows, width,
fpextra->limit_tuples,
&startup_cost, &run_cost);
}
else
@ -2907,6 +2945,14 @@ estimate_path_cost_size(PlannerInfo *root,
}
total_cost = startup_cost + run_cost;
/* Adjust the cost estimates if we have LIMIT */
if (fpextra && fpextra->has_limit)
{
adjust_limit_rows_costs(&rows, &startup_cost, &total_cost,
fpextra->offset_est, fpextra->count_est);
retrieved_rows = rows;
}
}
/*
@ -2915,7 +2961,8 @@ estimate_path_cost_size(PlannerInfo *root,
* the foreignrel's reltarget (see make_sort_input_target()); adjust tlist
* eval costs.
*/
if (fpextra && fpextra->target != foreignrel->reltarget)
if (fpextra && fpextra->has_final_sort &&
fpextra->target != foreignrel->reltarget)
{
QualCost oldcost = foreignrel->reltarget->cost;
QualCost newcost = fpextra->target->cost;
@ -2931,10 +2978,10 @@ estimate_path_cost_size(PlannerInfo *root,
* steps, before adding the costs for transferring data from the foreign
* server. These costs are useful for costing remote joins involving this
* relation or costing other remote operations for this relation such as
* remote sorts, when the costs can not be obtained from the foreign
* server. This function will be called at least once for every foreign
* relation without any parameterization, pathkeys, or additional
* post-scan/join-processing steps.
* remote sorts and remote LIMIT restrictions, when the costs can not be
* obtained from the foreign server. This function will be called at
* least once for every foreign relation without any parameterization,
* pathkeys, or additional post-scan/join-processing steps.
*/
if (pathkeys == NIL && param_join_conds == NIL && fpextra == NULL)
{
@ -2953,6 +3000,30 @@ estimate_path_cost_size(PlannerInfo *root,
total_cost += fpinfo->fdw_tuple_cost * retrieved_rows;
total_cost += cpu_tuple_cost * retrieved_rows;
/*
* If we have LIMIT, we should perfer performing the restriction remotely
* rather than locally, as the former avoids extra row fetches from the
* remote that the latter might cause. But since the core code doesn't
* account for such fetches when estimating the costs of the local
* restriction (see create_limit_path()), there would be no difference
* between the costs of the local restriction and the costs of the remote
* restriction estimated above if we don't use remote estimates (except
* for the case where the foreignrel is a grouping relation, the given
* pathkeys is not NIL, and the effects of a bounded sort for that rel is
* accounted for in costing the remote restriction). Tweak the costs of
* the remote restriction to ensure we'll prefer it if LIMIT is a useful
* one.
*/
if (!fpinfo->use_remote_estimate &&
fpextra && fpextra->has_limit &&
fpextra->limit_tuples > 0 &&
fpextra->limit_tuples < fpinfo->rows)
{
Assert(fpinfo->rows > 0);
total_cost -= (total_cost - startup_cost) * 0.05 *
(fpinfo->rows - fpextra->limit_tuples) / fpinfo->rows;
}
/* Return results. */
*p_rows = rows;
*p_width = width;
@ -3020,6 +3091,7 @@ adjust_foreign_grouping_path_cost(PlannerInfo *root,
List *pathkeys,
double retrieved_rows,
double width,
double limit_tuples,
Cost *p_startup_cost,
Cost *p_run_cost)
{
@ -3044,7 +3116,7 @@ adjust_foreign_grouping_path_cost(PlannerInfo *root,
width,
0.0,
work_mem,
-1.0);
limit_tuples);
*p_startup_cost = sort_path.startup_cost;
*p_run_cost = sort_path.total_cost - sort_path.startup_cost;
@ -5582,7 +5654,8 @@ postgresGetForeignUpperPaths(PlannerInfo *root, UpperRelationKind stage,
/* Ignore stages we don't support; and skip any duplicate calls. */
if ((stage != UPPERREL_GROUP_AGG &&
stage != UPPERREL_ORDERED) ||
stage != UPPERREL_ORDERED &&
stage != UPPERREL_FINAL) ||
output_rel->fdw_private)
return;
@ -5600,6 +5673,10 @@ postgresGetForeignUpperPaths(PlannerInfo *root, UpperRelationKind stage,
case UPPERREL_ORDERED:
add_foreign_ordered_paths(root, input_rel, output_rel);
break;
case UPPERREL_FINAL:
add_foreign_final_paths(root, input_rel, output_rel,
(FinalPathExtraData *) extra);
break;
default:
elog(ERROR, "unexpected upper relation: %d", (int) stage);
break;
@ -5809,7 +5886,7 @@ add_foreign_ordered_paths(PlannerInfo *root, RelOptInfo *input_rel,
* Build the fdw_private list that will be used by postgresGetForeignPlan.
* Items in the list must match order in enum FdwPathPrivateIndex.
*/
fdw_private = list_make1(makeInteger(true));
fdw_private = list_make2(makeInteger(true), makeInteger(false));
/* Create foreign ordering path */
ordered_path = create_foreign_upper_path(root,
@ -5826,6 +5903,241 @@ add_foreign_ordered_paths(PlannerInfo *root, RelOptInfo *input_rel,
add_path(ordered_rel, (Path *) ordered_path);
}
/*
* add_foreign_final_paths
* Add foreign paths for performing the final processing remotely.
*
* Given input_rel contains the source-data Paths. The paths are added to the
* given final_rel.
*/
static void
add_foreign_final_paths(PlannerInfo *root, RelOptInfo *input_rel,
RelOptInfo *final_rel,
FinalPathExtraData *extra)
{
Query *parse = root->parse;
PgFdwRelationInfo *ifpinfo = (PgFdwRelationInfo *) input_rel->fdw_private;
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) final_rel->fdw_private;
bool has_final_sort = false;
List *pathkeys = NIL;
PgFdwPathExtraData *fpextra;
bool save_use_remote_estimate = false;
double rows;
int width;
Cost startup_cost;
Cost total_cost;
List *fdw_private;
ForeignPath *final_path;
/*
* Currently, we only support this for SELECT commands
*/
if (parse->commandType != CMD_SELECT)
return;
/*
* No work if there is no FOR UPDATE/SHARE clause and if there is no need
* to add a LIMIT node
*/
if (!parse->rowMarks && !extra->limit_needed)
return;
/* We don't support cases where there are any SRFs in the targetlist */
if (parse->hasTargetSRFs)
return;
/* Save the input_rel as outerrel in fpinfo */
fpinfo->outerrel = input_rel;
/*
* Copy foreign table, foreign server, user mapping, FDW options etc.
* details from the input relation's fpinfo.
*/
fpinfo->table = ifpinfo->table;
fpinfo->server = ifpinfo->server;
fpinfo->user = ifpinfo->user;
merge_fdw_options(fpinfo, ifpinfo, NULL);
/*
* If there is no need to add a LIMIT node, there might be a ForeignPath
* in the input_rel's pathlist that implements all behavior of the query.
* Note: we would already have accounted for the query's FOR UPDATE/SHARE
* (if any) before we get here.
*/
if (!extra->limit_needed)
{
ListCell *lc;
Assert(parse->rowMarks);
/*
* Grouping and aggregation are not supported with FOR UPDATE/SHARE,
* so the input_rel should be a base, join, or ordered relation; and
* if it's an ordered relation, its input relation should be a base
* or join relation.
*/
Assert(input_rel->reloptkind == RELOPT_BASEREL ||
input_rel->reloptkind == RELOPT_JOINREL ||
(input_rel->reloptkind == RELOPT_UPPER_REL &&
ifpinfo->stage == UPPERREL_ORDERED &&
(ifpinfo->outerrel->reloptkind == RELOPT_BASEREL ||
ifpinfo->outerrel->reloptkind == RELOPT_JOINREL)));
foreach(lc, input_rel->pathlist)
{
Path *path = (Path *) lfirst(lc);
/*
* apply_scanjoin_target_to_paths() uses create_projection_path()
* to adjust each of its input paths if needed, whereas
* create_ordered_paths() uses apply_projection_to_path() to do
* that. So the former might have put a ProjectionPath on top of
* the ForeignPath; look through ProjectionPath and see if the
* path underneath it is ForeignPath.
*/
if (IsA(path, ForeignPath) ||
(IsA(path, ProjectionPath) &&
IsA(((ProjectionPath *) path)->subpath, ForeignPath)))
{
/*
* Create foreign final path; this gets rid of a
* no-longer-needed outer plan (if any), which makes the
* EXPLAIN output look cleaner
*/
final_path = create_foreign_upper_path(root,
path->parent,
path->pathtarget,
path->rows,
path->startup_cost,
path->total_cost,
path->pathkeys,
NULL, /* no extra plan */
NULL); /* no fdw_private */
/* and add it to the final_rel */
add_path(final_rel, (Path *) final_path);
/* Safe to push down */
fpinfo->pushdown_safe = true;
return;
}
}
/*
* If we get here it means no ForeignPaths; since we would already
* have considered pushing down all operations for the query to the
* remote server, give up on it.
*/
return;
}
Assert(extra->limit_needed);
/*
* If the input_rel is an ordered relation, replace the input_rel with its
* input relation
*/
if (input_rel->reloptkind == RELOPT_UPPER_REL &&
ifpinfo->stage == UPPERREL_ORDERED)
{
input_rel = ifpinfo->outerrel;
ifpinfo = (PgFdwRelationInfo *) input_rel->fdw_private;
has_final_sort = true;
pathkeys = root->sort_pathkeys;
}
/* The input_rel should be a base, join, or grouping relation */
Assert(input_rel->reloptkind == RELOPT_BASEREL ||
input_rel->reloptkind == RELOPT_JOINREL ||
(input_rel->reloptkind == RELOPT_UPPER_REL &&
ifpinfo->stage == UPPERREL_GROUP_AGG));
/*
* We try to create a path below by extending a simple foreign path for
* the underlying base, join, or grouping relation to perform the final
* sort (if has_final_sort) and the LIMIT restriction remotely, which is
* stored into the fdw_private list of the resulting path. (We
* re-estimate the costs of sorting the underlying relation, if
* has_final_sort.)
*/
/*
* Assess if it is safe to push down the LIMIT and OFFSET to the remote
* server
*/
/*
* If the underlying relation has any local conditions, the LIMIT/OFFSET
* cannot be pushed down.
*/
if (ifpinfo->local_conds)
return;
/*
* Also, the LIMIT/OFFSET cannot be pushed down, if their expressions are
* not safe to remote.
*/
if (!is_foreign_expr(root, input_rel, (Expr *) parse->limitOffset) ||
!is_foreign_expr(root, input_rel, (Expr *) parse->limitCount))
return;
/* Safe to push down */
fpinfo->pushdown_safe = true;
/* Construct PgFdwPathExtraData */
fpextra = (PgFdwPathExtraData *) palloc0(sizeof(PgFdwPathExtraData));
fpextra->target = root->upper_targets[UPPERREL_FINAL];
fpextra->has_final_sort = has_final_sort;
fpextra->has_limit = extra->limit_needed;
fpextra->limit_tuples = extra->limit_tuples;
fpextra->count_est = extra->count_est;
fpextra->offset_est = extra->offset_est;
/*
* Estimate the costs of performing the final sort and the LIMIT
* restriction remotely. If has_final_sort is false, we wouldn't need to
* execute EXPLAIN anymore if use_remote_estimate, since the costs can be
* roughly estimated using the costs we already have for the underlying
* relation, in the same way as when use_remote_estimate is false. Since
* it's pretty expensive to execute EXPLAIN, force use_remote_estimate to
* false in that case.
*/
if (!fpextra->has_final_sort)
{
save_use_remote_estimate = ifpinfo->use_remote_estimate;
ifpinfo->use_remote_estimate = false;
}
estimate_path_cost_size(root, input_rel, NIL, pathkeys, fpextra,
&rows, &width, &startup_cost, &total_cost);
if (!fpextra->has_final_sort)
ifpinfo->use_remote_estimate = save_use_remote_estimate;
/*
* Build the fdw_private list that will be used by postgresGetForeignPlan.
* Items in the list must match order in enum FdwPathPrivateIndex.
*/
fdw_private = list_make2(makeInteger(has_final_sort),
makeInteger(extra->limit_needed));
/*
* Create foreign final path; this gets rid of a no-longer-needed outer
* plan (if any), which makes the EXPLAIN output look cleaner
*/
final_path = create_foreign_upper_path(root,
input_rel,
root->upper_targets[UPPERREL_FINAL],
rows,
startup_cost,
total_cost,
pathkeys,
NULL, /* no extra plan */
fdw_private);
/* and add it to the final_rel */
add_path(final_rel, (Path *) final_path);
}
/*
* Create a tuple from the specified row of the PGresult.
*

3
contrib/postgres_fdw/postgres_fdw.h
Unescape View File

@ -188,7 +188,8 @@ extern List *build_tlist_to_deparse(RelOptInfo *foreignrel);
extern void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root,
RelOptInfo *foreignrel, List *tlist,
List *remote_conds, List *pathkeys,
bool has_final_sort, bool is_subquery,
bool has_final_sort, bool has_limit,
bool is_subquery,
List **retrieved_attrs, List **params_list);
extern const char *get_jointype_name(JoinType jointype);

16
contrib/postgres_fdw/sql/postgres_fdw.sql
Unescape View File

@ -349,6 +349,11 @@ EXPLAIN (VERBOSE, COSTS OFF)
SELECT count(c3) FROM ft1 t1 WHERE t1.c1 === t1.c2;
SELECT count(c3) FROM ft1 t1 WHERE t1.c1 === t1.c2;
-- ORDER BY can be shipped, though
EXPLAIN (VERBOSE, COSTS OFF)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
-- but let's put them in an extension ...
ALTER EXTENSION postgres_fdw ADD FUNCTION postgres_fdw_abs(int);
ALTER EXTENSION postgres_fdw ADD OPERATOR === (int, int);
@ -362,6 +367,11 @@ EXPLAIN (VERBOSE, COSTS OFF)
SELECT count(c3) FROM ft1 t1 WHERE t1.c1 === t1.c2;
SELECT count(c3) FROM ft1 t1 WHERE t1.c1 === t1.c2;
-- and both ORDER BY and LIMIT can be shipped
EXPLAIN (VERBOSE, COSTS OFF)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
-- ===================================================================
-- JOIN queries
-- ===================================================================
@ -506,7 +516,7 @@ SELECT t1.c1 FROM ft1 t1 WHERE EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c1)
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1 FROM ft1 t1 WHERE NOT EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c2) ORDER BY t1.c1 OFFSET 100 LIMIT 10;
SELECT t1.c1 FROM ft1 t1 WHERE NOT EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c2) ORDER BY t1.c1 OFFSET 100 LIMIT 10;
-- CROSS JOIN, not pushed down
-- CROSS JOIN can be pushed down
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
@ -613,6 +623,10 @@ 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;
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;
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 limit 1;
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 limit 1;
-- Aggregate is not pushed down as aggregation contains random()
explain (verbose, costs off)
select sum(c1 * (random() <= 1)::int) as sum, avg(c1) from ft1;

10
src/backend/optimizer/plan/planner.c
Unescape View File

@ -1830,6 +1830,7 @@ grouping_planner(PlannerInfo *root, bool inheritance_update,
bool final_target_parallel_safe;
RelOptInfo *current_rel;
RelOptInfo *final_rel;
FinalPathExtraData extra;
ListCell *lc;
/* Tweak caller-supplied tuple_fraction if have LIMIT/OFFSET */
@ -2389,6 +2390,11 @@ grouping_planner(PlannerInfo *root, bool inheritance_update,
}
}
extra.limit_needed = limit_needed(parse);
extra.limit_tuples = limit_tuples;
extra.count_est = count_est;
extra.offset_est = offset_est;
/*
* If there is an FDW that's responsible for all baserels of the query,
* let it consider adding ForeignPaths.
@ -2397,12 +2403,12 @@ grouping_planner(PlannerInfo *root, bool inheritance_update,
final_rel->fdwroutine->GetForeignUpperPaths)
final_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_FINAL,
current_rel, final_rel,
NULL);
&extra);
/* Let extensions possibly add some more paths */
if (create_upper_paths_hook)
(*create_upper_paths_hook) (root, UPPERREL_FINAL,
current_rel, final_rel, NULL);
current_rel, final_rel, &extra);
/* Note: currently, we leave it to callers to do set_cheapest() */
}

18
src/include/nodes/pathnodes.h
Unescape View File

@ -2439,6 +2439,24 @@ typedef struct
PartitionwiseAggregateType patype;
} GroupPathExtraData;
/*
* Struct for extra information passed to subroutines of grouping_planner
*
* limit_needed is true if we actually need a Limit plan node
* limit_tuples is an estimated bound on the number of output tuples,
* or -1 if no LIMIT or couldn't estimate
* count_est and offset_est are the estimated values of the LIMIT and OFFSET
* expressions computed by preprocess_limit() (see comments for
* preprocess_limit() for more information).
*/
typedef struct
{
bool limit_needed;
double limit_tuples;
int64 count_est;
int64 offset_est;
} FinalPathExtraData;
/*
* For speed reasons, cost estimation for join paths is performed in two
* phases: the first phase tries to quickly derive a lower bound for the

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