Re: OnLine Performance

In article <622aem$4h1@pepper.compnews.co.uk>, "Jon says... > >Q. can I tweak any of the onconfig parameters, also shown below, to increase >performance ? > >Q. is the buffwrits - cache% shown below to low ? I increased my buffers in >an attempt to bump it up, this worked jumping it from 60% to 71%. > Your write % is poor. You should aim for 90% if possible. You don't say how much physical memory you have, but Informix recommend using up to 25% of the available memory for BUFFERS. Try bumping it up high - say 25000, or higher if you can. Then gradually reduce it until your cache rate suffers again. You might also consider increasing your checkpoint interval time to, say 900 seconds. This is a trade-off; dirty pages remain for longer in the cache thus offering a potential reduction in physical i/o, but on the other hand recovery times are longer in the event of system failure. Are your logical and physical logs in your root dbspace? If so, you might try i/o balancing by moving them onto separate disks. An onstat -D would help analyse this. Use onstat -g ses and onstat -g sql to see what SQL your user sessions and executing. Neil Truby Chase Manhattan Bank Bournemouth, UK neil.truby@chase.com