Re: Changing First extent size by updating systables

>From: Terry Boyland <Terry@century.demon.co.uk> >Date: Wed, 15 Nov 95 10:12:02 GMT >X-Informix-List-Id: <news.18895> > >My understanding is that the extent relates to physical contiguous >space on disk or in other words the actual positioning of data on the >disk. As this data is currently stored in extents it would seem >logical that at some point the data would have to be unloaded and >then deleted. Afterwards it should be loaded back into a bigger >space. > >I can't see at this moment how changing the index will do this. If you do ALTER INDEX idxname TO CLUSTER, the table is rebuilt with the data physically ordered so that the rows in the data pages are in the same order as they are in the index, the advantage being that you should then be doing sequential reads of the data when accessing it via the index. Effectively, ALTER INDEX idxname TO CLUSTER does the unload, load, and delete to which you refer. ALTER TABLE statements which involve rebuilding the table (adding/dropping a column, for example), would also do this. Yours, Jonathan Leffler (johnl@informix.com) #include <disclaimer.h>