Thanks for the quick response. This is exactly what I was looking for.
If you can help me, I do not know how to use explain plan. After I ran utlxplan.sql script what do I do ?
I have ran following:
ANALYZE index index_name validate structure and COMPUTE STATISTICS;
but I don't know how to use it to find out what happens with the index.
We have about 150 indexed columns, do I have to do this for each column- index seperately ?
What if I have a unique composite index on column (a, b, c)
and I use just a or a, b in my where clause ? Does index gets used ?
How do I know if I am doing RULE based or COST based optimization ?
If you have any scripts could you please send it to me:
[email protected]

Thanks a lot
Sonali