Thanks for the inputs.

I aware that when the optimizer mode is choose, what will happen.
Now my question is some thing over that. There is a column in v$sql called optimizer_mode. when i queired count for this, I got the output as given in my earlier post.

So if query a particular record in the v$sql, It should tell me whether it has used CBO or RBO right?

But when i queried the v$sql it is giving me inputs like 'CHOOSE', 'RBO' and 'NONE'.

As my optimizer mode is CHOOSE. I would like to know what all the queries used CBO and RBO till. I dont what for the future sqls. I want this info only for the sqls in the v$sql view.

To keep this precisely, I want his, I have queried v$sql for a record, then i got the value for the optimizer mode as 'CHOOSE', this is not telling me whether it has used CBO or RBO.

Sorry friends, I think I am confusing all of you.

This is very useful for me.