Re: Question on 7.12 Optimizer

V Crouch (tiger@sky.net) wrote: : Could you please help me solve a puzzle? I have a "test" database and a : "production" database, both which are configured the same. I have a table : with about 1.3 million rows in it, in both test and prod. The table : contains names and addresses. I have an application that does a lookup : based on the first part of the name (i.e. SELECT ...WHERE name is LIKE : ...). For both test and prod, I've recently built an index on the lookup : column, and I've updated statistics at the database, table, and column : level. The only difference between test and prod is that the test table is : fragmented across 3 dbspaces, while the prod one is not. : The mystery is this: On test, my query uses the index, while the prod : query does a sequential scan. Any thoughts on why this might occur, or : what I can do to force the optimizer to use the index? I would really : appreciate some assistance. I also face this problem on update statistics medium or high. In my opinion, if you would like to use index searching, you better update statistics medium; though the performance may not be optimize.