RE: number of extents

After you reach the maximum number of extents, you will be unable to insert more rows into your table. A large number of extents will also adversely impact database performance. The maximum number of extents for 2K page systems is approximately 200. To quote the Informix training material on this subject: "The more con-contiguous extents that are read, the more seek time will be added to data transfer time. ... The maximum number of extents is calculated as: max#extents <= ( pagesize - ((4 * number of column in table) + ( 8 * number of BLOB and VARCHAR columns + 136 ) + (12 * number of indexes) + ( 4 * number of columns in the indexes) + 84 ))" You can find more information on this subject at the following Web address: http://www.markscranton.com Click on: Monthly Topic -> January 15 - Extents and extent sizing Good luck with your database reorganization efforts. Rick -----Original Message----- From: MATTHEW H. DEVLIN [mailto:the_griffon@my-deja.com] Sent: Saturday, December 25, 1999 8:03 PM To: informix-list@iiug.org Subject: Re: number of extents If 240 is correct what will happen with a table that reaches that number? In article <8412im$lt1$1@taliesin2.netcom.net.uk>, "Neil Truby" <ntruby@netcomuk.co.uk> wrote: > I think there is still a maximum number of extents, whose precise value is > subject to an impentetrable formula, of around 240 extents. > > MATTHEW H. DEVLIN wrote in message <84040r$bhb$1@nnrp1.deja.com>... > >I think I remember reading somewhere that with newere versions of IDS > >you did not need to worry about the number of extents. Is this > >correct? I have some tables with over 100 extents and I suspect that > >they are severely fragmented. I am formulating a plan for fixing this > >situation as well as setting up a good data distribution (fragmentation) > >Plan. should I be concerned with the extents? > > > > > >Sent via Deja.com http://www.deja.com/ > >Before you buy. > > Sent via Deja.com http://www.deja.com/ Before you buy.