Re: Large table extents

This is a multi-part message in MIME format. --------------488FDE545B5 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Jonathan Leffler wrote: > >I ask this because that is what seems to be happening and if it is, then > >we need a way to defragment the table extent. > > > >I would think that this means unloading and re-loading the table. > > Or doing an ALTER TABLE, or, more plausibly, an ALTER INDEX TO CLUSTER. > These are simpler, and should be quicker. However, you have to keep in mind that the DOWNSIDE to an alter table or alter index is that it requires that there be enough free space in the target dbspaces to hold the OLD copy of the table and the NEW copy of the table simultaneously (at least temporarily, as the old copy is dropped when the new one is complete). When someone talks about LARGE tables, I'm inclined to assume this free space would NOT be available until informed otherwise. The other thing to watch out for is when there is enough total free space for this, what is the distribution of that free space in the dbspaces? If the free space is made up of many small free blocks, as opposed to one large contiguous block, then the new table may be in worse shape than the old one. While an unload may take longer, it is much more likely to avoid these potential problems. -- Dave Kosenko, Informix Professional Services **************************************************************************** While it is true that there is more than one way to skin a cat, the cat himself generally fails to appreciate the differences. --------------488FDE545B5 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="IFXDISCL.TXT" ************************************************************************* Note: please do not send me email asking about features, or asking about Informix problems and how to solve them. I answer what questions I can in this forum (comp.databases.informix) when I have the time to spare. For questions on features, call your local sales rep or check out the Informix web site (http://www.informix.com). For technical problems, call Informix tech support. ************************************************************************* Disclaimer: All opinions expressed in this message are well-reasoned and insightful; needless to say, they are not those of Informix Software, its partners or lackeys. Anyone who says otherwise is itching for a fight. --------------488FDE545B5--