I was having a discussion with a junior DBA the other day about whether tables and indexes need to be in separate tablespaces and the issue of concurrent access came up. My position is that Oracle always reads the index and the uses the rowid(s) to access the table. There is no issue of concurrent access. However, she pulled out the latest and greatest Oracle 11 book and sure enough the author repeated the old myth about concurrent access and the need to separate indexes and tables. How can you fight this? With SANs and logical disks there's no certainty that separate tablespaces means that you're using separate read/write heads. I'm getting as tired of this argument as I am of the RAID5 argument. It shouldn't even be a point of discussion. Doesn't Oracle have a vested interest in seeing that books about Oracle have correct information or does that just make for more opportunities for Oracle Consulting?