The way the statement is written appears to imply that the tablespace in question is on one real physical disk and that when the indexes are separated into a different tablespace the index tablespace will be put on a different physical disk. In this particular case separating the tables and indexes probably would help performance providing there are multiple sessions on the database that access other objects in the same tablespace concurrently. Two disks are normally better than one. The problem is just about no one has this type of disk arrangement any more. The world is logical disks made up of multiple physical devices arrayed in RAID-0, RAID-5, or RAID-10 collections. -- Mark D Powell -- Phone (313) 592-5148 ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of David Aldridge Sent: Thursday, May 15, 2008 4:32 PM To: davidsharples@xxxxxxxxx; ricks12345@xxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Subject: Re: concepts document part about separating indexes and tablspaces It's actually in the DBA Guide, and it's still there now: http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/indexes.h tm#i1006372 "Using different tablespaces (on different disks) for a table and its index produces better performance than storing the table and index in the same tablespace. Disk contention is reduced." ----- Original Message ---- From: David Sharples <davidsharples@xxxxxxxxx> To: ricks12345@xxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Sent: Thursday, May 15, 2008 3:18:48 PM Subject: Re: concepts document part about separating indexes and tablspaces because it doesn't 2008/5/15 Rick Ricky <ricks12345@xxxxxxxxx>: i was talking to someone about this today. I cannot remember where in the Concepts document that it says that separating data from indexes improves performances?