RE: Do extents impact speed?

Several good points have been made about the improvements in SAN technology and how this does or does not affect the extent issue. A few months ago, Maury Tiller of Network Appliances came to demo their data storage appliance, an extraordinary new storage technology. With this, the physical location of the data makes no real difference. I have to admit, the numbers were very impressive. The majority of our customers, and possibly Malcolm's, are not using such technology. Some are using fairly modern SAN's and not, therefore, seeing as much performance degradation with interleaving as we would otherwise expect. However, when our customers have reorganised, most of them have reported an improvement in performance, including one using one of the latest IBM Shark SAN's. I would love to give you benchmark data, percentages, and figures, but I was not doing the database administration on the project. For the customer with the Shark, we also parallelized their largest tables, which has a bigger impact. However, I can state, from experience, that reducing the extents improved performance. Sincerely, Christopher Coleman Steering Committee President Kansas City Informix Users Group www.iiug.org/kciug Database Analyst Pharmacy Division Mediware Information Systems, Inc. 913/307-1073 sending to informix-list