400 | 400
(4 rows)
--- with PHVs, partition-wise join selected but no join pushdown
+-- with PHVs, partitionwise join selected but no join pushdown
EXPLAIN (COSTS OFF)
SELECT t1.a, t1.phv, t2.b, t2.phv FROM (SELECT 't1_phv' phv, * FROM fprt1 WHERE a % 25 = 0) t1 FULL JOIN (SELECT 't2_phv' phv, * FROM fprt2 WHERE b % 25 = 0) t2 ON (t1.a = t2.b) ORDER BY t1.a, t2.b;
QUERY PLAN
SELECT t1.a,t1.b FROM fprt1 t1, LATERAL (SELECT t2.a, t2.b FROM fprt2 t2 WHERE t1.a = t2.b AND t1.b = t2.a) q WHERE t1.a%25 = 0 ORDER BY 1,2;
SELECT t1.a,t1.b FROM fprt1 t1, LATERAL (SELECT t2.a, t2.b FROM fprt2 t2 WHERE t1.a = t2.b AND t1.b = t2.a) q WHERE t1.a%25 = 0 ORDER BY 1,2;
--- with PHVs, partition-wise join selected but no join pushdown
+-- with PHVs, partitionwise join selected but no join pushdown
EXPLAIN (COSTS OFF)
SELECT t1.a, t1.phv, t2.b, t2.phv FROM (SELECT 't1_phv' phv, * FROM fprt1 WHERE a % 25 = 0) t1 FULL JOIN (SELECT 't2_phv' phv, * FROM fprt2 WHERE b % 25 = 0) t2 ON (t1.a = t2.b) ORDER BY t1.a, t2.b;
SELECT t1.a, t1.phv, t2.b, t2.phv FROM (SELECT 't1_phv' phv, * FROM fprt1 WHERE a % 25 = 0) t1 FULL JOIN (SELECT 't2_phv' phv, * FROM fprt2 WHERE b % 25 = 0) t2 ON (t1.a = t2.b) ORDER BY t1.a, t2.b;
PartitionSchemeData objects and makes it easy to compare the partition schemes
of joining relations.
-Partition-wise aggregates/grouping
-----------------------------------
+Partitionwise aggregates/grouping
+---------------------------------
If the GROUP BY clause has contains all of the partition keys, all the rows
that belong to a given group must come from a single partition; therefore,