I have several DR$ tables in my database. I think they come because I am using text indexes. This is third party application. When I run dbms_stats to do statistics on entire schema, it never calculates statistics on DR$ tables. Somewhere I had read that Oracle uses rule base optimizer , yes rule based optimizer for these tables. I am on Oracle 10.2.0.4. When I rebuild text indexes, it never computes statistics on these tables as well.
What is stage that some of my queries involving text indexes run slow that database control (database tuning advisor) is recommending run statistics on these tables!!! Can someone provide their thoughts on it?