Hi all,I have 2 tables:table1 (field1,field2,.....) table2 (field1,field2,field3,.....) field1 is an uuid type
field2 is a timestamp with time zone type.If I execute:explain (analyze on, timing off) select B.field3,A.field1,A.field2 FROM table1 A INNER JOIN table2 B using (field1,field2)the query plan is QUERY PLAN ---------------------------------------------------------------------------------------------------------------- Hash Join (cost=137324.20..247200.77 rows=1 width=31) (actual rows=1136175 loops=1) Hash Cond: ((b.field1 = a.field1) AND (b.field2 = a.field2)) -> Seq Scan on table2 b (cost=0.00..49694.75 rows=1136175 width=31) (actual rows=1136175 loops=1) -> Hash (cost=89610.68..89610.68 rows=2287368 width=24) (actual rows=1143684 loops=1) Buckets: 65536 Batches: 4 Memory Usage: 15699kB -> Seq Scan on table1 a (cost=0.00..89610.68 rows=2287368 width=24) (actual rows=1143684 loops=1) Total runtime: 5055.118 ms(7 rows)My question isWhy Have I a rows=1 in the explain and rows=1136175 in the explain analyze?
I tried to tune Planner Cost Constants asdefault_statistics_target (integer)
and / or from_collapse_limit (integer)join_collapse_limit (integer)
pgsql-general by date:
Соглашаюсь с условиями обработки персональных данных