John R Pierce wrote: > in our case, our production systems are a very large very complex > realtime oracle database running on large scale Sun enterprise hardware > on bigiron EMC storage, using dozens and dozens of raid10 logical > volumes as you do NOT want to have a single 10TB volume, sorry. by > hand optimizing the tablespace layouts of the applications tables and > indicies, which have very specific access patterns, we can get double > the throughput of the blind 'just stripe the universe' approach. Since Oh you would not have a single 10TB volume of course: and it is still a little quaint to hand optimize tablespaces. That is something we did in the 90s. Our own tests on multi-TB databases and modern SAN systems, the shotgun approach beat hand optimization every time. And we are talking about people with dozens of years with SQL optimization behind them. Intelligent I/O prefetch adaption, intelligent and dynamic access plans... the world of performance in the RDBM world is changing and old rules for performance are changing with it. -- //Morten Torstensen //Email: morten at mortent.org //IM: Cartoon at jabber.no morten.torstensen at gmail.com And if it turns out that there is a God, I don't believe that he is evil. The worst that can be said is that he's an underachiever.