Help in tuning.

Question

I have a column called b_month and I its not an index column. But, in my query I need to apply a where clause on that column with some conditions like this.
and extract(month from b_month)=11
and extract(year from b_month)=2007
The table has approx 4 mil records. I changed the condition in this format:
     and b_month = to_date('11/01/2007','MM/DD/YYYY')
Still there is no improvement in performance. IS there any other way to handle this apart from creating an index on that column.
Appreciate your feedback.

Answer 1

You have few options if you cannot add an index:
1) Partition the table by b_month
2) I assume you cannot create an index because you are concerned about impacting other queries. You could create a function-based index on this column turning it into a month number. Then other queries running against this table using the date will not use this index.
3) Add a /*+ parallel(table degree) */ hint to this query to speed up the full table scan. See:
http://www.singlequery.com/?p=49
Greg Pike