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| author | Robert Haas <rhaas@postgresql.org> | 2016-03-09 10:51:49 -0500 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2016-03-09 10:51:49 -0500 |
| commit | aa09cd242fa7e3a694a31f8aed521e80d1e626a4 (patch) | |
| tree | f59e3056c8fc5d461c89e906a5aa74eb167ff926 /contrib/postgres_fdw/sql/postgres_fdw.sql | |
| parent | d31f20e2b5a246f276c73134b610ac7a2f34e274 (diff) | |
| download | postgresql-aa09cd242fa7e3a694a31f8aed521e80d1e626a4.tar.gz postgresql-aa09cd242fa7e3a694a31f8aed521e80d1e626a4.zip | |
postgres_fdw: Consider foreign joining and foreign sorting together.
Commit ccd8f97922944566d26c7d90eb67ab7848ee9905 gave us the ability to
request that the remote side sort the data, and, later, commit
e4106b2528727c4b48639c0e12bf2f70a766b910 gave us the ability to
request that the remote side perform the join for us rather than doing
it locally. But we could not do both things at the same time: a
remote SQL query that had an ORDER BY clause would never be a join.
This commit adds that capability.
Ashutosh Bapat, reviewed by me.
Diffstat (limited to 'contrib/postgres_fdw/sql/postgres_fdw.sql')
| -rw-r--r-- | contrib/postgres_fdw/sql/postgres_fdw.sql | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql index 95e00ebcbf9..4b88a301f89 100644 --- a/contrib/postgres_fdw/sql/postgres_fdw.sql +++ b/contrib/postgres_fdw/sql/postgres_fdw.sql @@ -237,6 +237,11 @@ SELECT t1.c1, t2."C 1" FROM ft2 t1 JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFF EXPLAIN (VERBOSE, COSTS false) SELECT t1.c1, t2."C 1" FROM ft2 t1 LEFT JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFFSET 100 LIMIT 10; SELECT t1.c1, t2."C 1" FROM ft2 t1 LEFT JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFFSET 100 LIMIT 10; +-- A join between local table and foreign join. ORDER BY clause is added to the +-- foreign join so that the local table can be joined using merge join strategy. +EXPLAIN (COSTS false, VERBOSE) + SELECT t1."C 1" FROM "S 1"."T 1" t1 left join ft1 t2 join ft2 t3 on (t2.c1 = t3.c1) on (t3.c1 = t1."C 1") OFFSET 100 LIMIT 10; +SELECT t1."C 1" FROM "S 1"."T 1" t1 left join ft1 t2 join ft2 t3 on (t2.c1 = t3.c1) on (t3.c1 = t1."C 1") OFFSET 100 LIMIT 10; RESET enable_hashjoin; RESET enable_nestloop; |