Re: 7.23 UC4 vs. 7.30 UC3
Posted in 1998
snip... > >> Also, Oyvind, we have experienced the wrong query path being selected by the > >> optimizer is 7.x for some time. We understand that 7.30 allows the user (us) > >> to control the query optimizer more directly. > > > >Yes, we have used this feature to verify that the optimizer chose the > >wrong query path. The cost was _much_, _much_ lower when we suggested the > >correct index. However this is something I would hesitate to use in a > >production environment. It is extremly painful to maintain. snip.... I've done a lot of performance tuning, and most of the time when the optimizer chooses the wrong path its because it needs better statistics to push it in the right direction. Have you explored this angle yet? Its really preferable to hardwiring hints into your code. Greg