Re: Infromix & Data Warehousing Solutions

Tim, Thanks for the info but we're not on the same page. I'm not talking about the Informix query optimizer (access plan shown by 'explain plan'). There's tons of info on www.informix.com on that optimizer. I'm talking about the new MetaCube Warehouse Optimizer. My understanding is that it: .. takes the 'audit' info from MetaCube about existing queries. .. creates an analytical performance model (methodology unknown) .. adds hypothetical aggregate tables to the 'schema' .. re-evaluates the model to generate estimated query elapsed times. Dr. Chandra presented some nice plots that showed elapsed times decreasing (and leveling off) and storage requirements increasing (and leveling off) as N aggregates were added. She said that the next version would also recommend some number of indexes with the same performance vs. storage trade-offs. Given the difficulty of designing data warehouses and marts, this seems like it could be an incredibly useful tool. I was just wondering if anyone has used it. > The optimizer can only be as good >as your best implementation of the data base. So all that stuff >about fragmentation, disk layouts, and classic table design are really >important. If not done right, no optimizer on either Metacube or XPS >will do much good.