I don't buy the space saving thing (there might be dictionary performance improvements of course). I'm pretty certain that each of your empty tables *if *they had an initial segment created would "waste" 64k (8 8k blocks) of space, that's 625mb for every 10,000 empty objects (it'll probably be a bit more with bitmap extent maps filling I suppose). It strikes me that people who worry about a wasted few hundred mb in a schema that size are probably either overly obsessive, unbelievably effective or just looking in the wrong place for space savings. :) On Mon, Nov 26, 2012 at 11:17 AM, Norman Dunbar <oracle@xxxxxxxxxxxxxxx>wrote: > Hi Dominic, > > On 26/11/12 11:13, Dominic Brooks wrote: > > I know you have a workaround on your blog and the main point is that > > dbms_tt should probably warn about these, but just wanted to point out > > that you can materialise these deferred segments using > > dbms_space_admin.materialize_deferred_segments. > > Yes, I know about this, thanks all the same, but in a huge database, > which this one isn't, imaging the result of materiali[zs]ing all those > empty tables again. The point of the deferred segment creation is to > save space - which it does, admirably - seems a shame to have to undo > all that good work when we need to downgrade/migrate it to a Standard > Edition database. > > > Cheers, > Norm. > > -- > Norman Dunbar > Dunbar IT Consultants Ltd > > Registered address: > Thorpe House > 61 Richardshaw Lane > Pudsey > West Yorkshire > United Kingdom > LS28 7EL > > Company Number: 05132767 > -- > //www.freelists.org/webpage/oracle-l > > > -- Niall Litchfield Oracle DBA http://www.orawin.info -- //www.freelists.org/webpage/oracle-l