Hint cardinality for predicate
- From: Ilia Kantor <iliakan@xxxxxxxxx>
- To: Oracle-L@xxxxxxxxxxxxx
- Date: Wed, 12 May 2010 23:53:52 +0400
Hello,
I have a multi-predicate query like:
SELECT * FROM table WHERE
a BETWEEN 5 and 10
and
b in (3,4,5)
and c in (9)
...
Unfortunately, optimizer is not very good at estimating cardinalities.
Columns are somewhat intercorrelated and "multiple column stats"
feature does not fix that.
Although, I gather my own stats which give me exact idea for
selectivity of each predicate.
How can I pass this information to optimizer?
I found COLUMN_STATS which can adjust stats for column, but I have
not just column stats, I have exact selectivity of each predicate for
this query, which I'd like to
supply for the optimizer to choose best plan.
Maybe OPT_ESTIMATE may be a help? Rewriting query to make subselect of
each predicate?
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