Given that you have a fairly firm prediction about rates of growth (3GB per month) I would set an extent size that allowed me to see if the rate diverged too rapidly from the expected level. At 1GB extents, you can get a report every 10 days that an extent has been added - not too frequent, not so far apart that you might forget about checking. You might want to think about testing allocation time at this size (it shouldn't be large on LMTs) and if it is surprisingly large, pre-allocate some hours ahead of schedule at an off-peak time (if you have one). (I usually go for 1 extent per month - but I feel queasy at 3GB extents, for no scientific reason at all). Regards Jonathan Lewis http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/seminar.html Public Appearances - schedule updated Dec 23rd 2004 ----- Original Message ----- From: "Roger Xu" <roger_xu@xxxxxxxxxxx> To: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>; "Oracle-L@Freelists. Org (E-mail)" <oracle-l@xxxxxxxxxxxxx> Sent: Friday, January 07, 2005 10:04 PM Subject: RE: automatic extent allocation Thanks for the discussions regarding the max # of extents. Any take on uniform extent allocation? Thanks. -- //www.freelists.org/webpage/oracle-l