WITH Clause Performance
Is there performance penalty of using WITH clause?
For example:
with t as(
select 1 from dual
),
x as (
select 1 from dual
)
select * from t, x
versus
select 1 from dual t, dual x
When i run explain plan, it shows the same. I am wondering for more complex query. Thank you.
SELECT STATEMENT ALL_ROWSCost: 4 Cardinality: 1
3 NESTED LOOPS Cost: 4 Cardinality: 1
1 FAST DUAL Cost: 2 Cardinality: 1
2 FAST DUAL Cost: 2 Cardinality: 1