Обсуждение: Predicate information in EXPLAIN Command
Hello,
I am trying to find predicate information for a given SQL query plan as provided by Oracle using DBMS_XPLAN. I am looking at the EXPLAIN command for getting this query plan information, with no luck so far.
Does the EXPLAIN command provide predicate information?
Thank you
Sameer
On 14.05.2013 12:23, Sameer Thakur wrote: > Hello, > I am trying to find predicate information for a given SQL query plan as > provided by Oracle using DBMS_XPLAN. I am looking at the EXPLAIN command > for getting this query plan information, with no luck so far. > > Does the EXPLAIN command provide predicate information? Sure. For example, postgres=# explain select * from a where id = 123; QUERY PLAN --------------------------------------------------- Seq Scan on a (cost=0.00..40.00 rows=12 width=4) Filter: (id = 123) (2 rows) The predicate is right there on the Filter line. Likewise for a join: postgres=# explain select * from a, b where a.id = b.id; QUERY PLAN ----------------------------------------------------------------- Hash Join (cost=64.00..134.00 rows=2400 width=8) Hash Cond: (a.id = b.id) -> Seq Scan on a (cost=0.00..34.00 rows=2400 width=4) -> Hash (cost=34.00..34.00 rows=2400 width=4) -> Seq Scan on b (cost=0.00..34.00 rows=2400 width=4) (5 rows) The join predicate is on the Hash Cond line. - Heikki