diff options
Diffstat (limited to 'contrib/postgres_fdw/sql/postgres_fdw.sql')
| -rw-r--r-- | contrib/postgres_fdw/sql/postgres_fdw.sql | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql index 301af4091ee..c588c96727c 100644 --- a/contrib/postgres_fdw/sql/postgres_fdw.sql +++ b/contrib/postgres_fdw/sql/postgres_fdw.sql @@ -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; |