Re: Fragments

Albert Wisse wrote: > > Hello, > > I want to verify if I am right: > > I think using fragments make sense in the following case: > > My hardware is: Sun Enterprise server with 4 * 250 MHZ CPU's (NUMCPUVPS > = 3) > Internal memory 1280MB > Sparc Enterprise Network Array (SENA) disk-subsystem > > The disksubsystem has 2 times five disk in use for Informix. > I use RAID level 0+1, five disks in a strip set with a strip size 16K. > The disksubsystem is connected by two channels to the server and load > determines which cannel is used. > If I am right then I can see the disksubsystem as at least two big > disks, so > fragmenting my tables make sense. > > In general with stripped and/or mirrored disks can you say then that > fragmenting will > boost performance. Yes it will by a) putting multiple CPUs to work in scans and b) eliminating fragments where possible. BTW: You will have to break up the stripe into mulitple logical drives each <2GB for Informix to be able to use it. Also for ease of administration I hope you have striped 5 mirrored pairs rather than mirroring 2 stripe sets. Art S. Kagel