partitioned table refusing to use partitioned index

Interesting situation, I have a 1M row partitioned table. Split across four drives, the index is likewise split and another set of drives. I can understand the optimizer not using the partitioned index if it deems that a full partition scan is more efficient. However, I do not understand why the index is not used when it is explicitly stated in the INDEX hint. Furthemore the optimizer is 'locked' if you will to use the CBO by having the mode set to FIRST_ROWS in the init.ora file.

The SQL that is being run is an UPDATE statement that uses part of the unique key. The key is an OID plus a fixed character identifier for location, i.e. '001','025','030', etc. When using the update against an identical, non-partitioned table with the same key the index is used witout ant hints present in the SQL.

So what am I overlooking? Received on Tue Jan 15 2002 - 14:53:14 CET