Re: Performance problem with big table!

Okay....Giving bits and pieces makes it very hard to help. > Indexes are detached and located in other dbspaces! What about the data? How are you fragmenting the data? Round robin? Expression? If the latter, what expression? > select field1, field2, field3 from table where field1 = x> > (field1 is integer and indexed/unique) > > And it worked! We run the debugger and seen that the index is NOT used!!! > Why? It worked during one week. So let me repeat: Have you run update statistics? Are you using PDQ? How many physical disks is your table spread across? Show the following: * Your table schema * Your create index statement * Your onconfig file * Your hardware configuration * The exact version of IDS 7.31 and your OS At the least, you need to indicate if you've run update statistics, because that's the most likely culprit without knowing more.