Re: Help calculating extents from esql-c

Well Tonto... If you've got enough log files and enough contiguous table space, the alter index cluster will create a temporary version of your table, fill it with sorted rows and swap it for the old version of your table. This has a number of useful effects. 1. It frees any extents which are empty. 2. It should (if you have the space) re-create the table with a single extent. It hasn't changed the initial extent size, it's just "defragged" your table. 3. It sorts the rows of your table to match the order of the index you altered. This can really help speed up searches based upon the index. But, if your table changes frequently, the effect will soon fade. Perhaps you could describe the effect your trying to achive. It sounds, though, like you could use this to defragment your table. Then, you could boost the next extent size and live happily for a while. It might also be worth while to drop and re-create the indexes for the table to compress and optimize them as well. For tables which change drastically, I've automatted these steps as a nightly cron job. --Craig (craig@chemistry.utah.edu) > > OK keemosabee what does this do, sounds very interesting. > > does it actually modify the initial extent or move the table > to a temp and create a new one with the proper extents or like > what ?? > > > CRAIG@CHEMISTRY.CHEM.UTAH.EDU wrote: > >Randy, > > > > Why not just use "alter index to cluster" and "alter index to not cluster" > >to fix your extents automagically? If you must, the sizes can be > >calculated although it's a pain to do it right. (Right meaning > >calculating the index sizes + overhead, data sizes + overhead, > >table overhead, etc.) > > > > --Craig (craig@chemistry.utah.edu) > >