7.3 Optimizer diffs from 7.2

We just upgraded to 7.3 from 7.2. Complex queries run the same or even faster  than with 7.2. However, primary keys/indexes seem to be ignored, and do ing  FT scans. We either have to force the rule based optimizer in init.ora (which  makes complex queries run slow) or force it by deleting the statistics before  loading (which does the primary key lookups) and then re-estimating after.  What did Oracle do to the optimizer to have this effect, has anyone else seen  it, and does anyone have any other suggestions?

Note: The first thing we did was compute (estimate) statistics for every  object (using 30% of rows), thinking they should be re-estimated for the new  optimizer, but this had little or no effect. Received on Fri Nov 14 1997 - 00:00:00 CST