Re: Informix 7.1 on Digital UNIX - raw or cooked?

WF Software wrote: > > In article <6tkbit$7gh$1@news.xmission.com>, > David.Ashby@workcover.nsw.gov.au (Ashby, David) wrote: > > > > > > > The decision to go raw or cooked should not just be based on > > performance. A more important consideration in my opinion is > > recoverability. With a cooked file system IO's are fed to the OS for > > writing, in a worst case scenario the following could happen: > > - the server crashes > > - Informix believes that a buffer has been written to disk > > - but the OS has cached it and it has not been written > > - when Informix is brought back online it does not recover the > > suspect page > > > > If you can use KIO with raw chunks I believe that the OS cache is not > > used. > [cutting] > > I accept the above but I read the question as to whether to use raw disk > or Digital OS because its rumoured to be quick. Use RAW disk. It is as much as 30% faster on ALL platforms that I am aware of. If you have doubts, I guarantee that DEC has an Informix benchmark team that can give you advice and has probably already written up their tuning secrets in a white paper. Contact DEC. Art S. Kagel