Re: understanding On-Line's Optimizer

Steve Romankiw wrote: > > I am new the Informix On-Line engine. I am looking for information on > On-Line v7.13 Cost Based Optimizer. We are migrating to Informix from > SQLBase and the optimizers work differently. In informix, we often get > sequential scans on queries that we feel should be using an index. > > Do you know of any books or white papers on the subject? > > Thanks. > > Steve Romankiw > Executive Risk Inc. > sromankiw@execrisk.com steve, try the 'informix-online dynamic server performance guide'. it's a small manual, yet packed with a lot of good information on performance tuning from the engine to the application. it covers the query optimizer and it's bottom-up, breadth-first search strategy, indexing strategies, sqexplain.out info - the whole lot. l8rm8. -jason