All, What i meant is even if there is no statsitics, CBO will be used if we speicy Hints(ALL_ROWS, FIRST_ROWS_n). This is what i understood.

ALL_ROWS
The optimizer uses a cost-based approach for all SQL statements in the session regardless of the presence of statistics and optimizes with a goal of best throughput (minimum resource use to complete the entire statement).

FIRST_ROWS_n
The optimizer uses a cost-based approach, regardless of the presence of statistics, and optimizes with a goal of best response time to return the first n number of rows; n can equal 1, 10, 100, or 1000.




Quote Originally Posted by davey23uk
i think he means that even if there are no stats the cbo will still be used if those hints are used.

not sure of the point of the post though