Re: Major performance problems with Informix Online

General wrote: > > Hi, > > We upgrade from Informix SE to Informix Online about a week ago and > since then have been experiencing significant performance problems; > significant enough to make the system virtually unusuable. Queries > which previously took 2 or 3 seconds are escalating up to 1-2 minutes. > > Our support people have all drawn blanks and we are now even > considering wiping the box and resorting back to the old version by > restoring from tape (thus losing a weeks worth or work and data). > > We suspect the problem could be with the configuration of Online and > would appreciate any assistance which is available. > > The configuration of the box is as follows: > > Siemens Nixdorf RM600 containing > 8 RISC Processors > 900MB RAM > 80GB Disk Space > Approximately 60-80 users. > It's running a Patient Administration System > > Below is a copy of the online configurations (there are two on our box > and i'm not sure which is being used.) > > onconfig.camis_l: > > Assistance is urgently required; please e-mail > petew@grimhosp.demon.co.uk > > Thanks > > Pete Did you do an UPDATE STATISTICS after your conversion? If you didn't, OnLine will be able to make scant use of your database's indexes, and will therefore show a great deal of sequential scanning in place of index reads. It's a little worrying that you don't know which configuration file. Assuming your instance is initiated with user informix, check what the environment variable $ONCONFIG is set to. Assuming that you're using the first of the files you supplied, you should be able to increase BUFFERS somewhat with 900M of physical memory. Additional informiation that would help: how many processors do you have?; can you provide output from onstat -p? Neil Truby Chase Manhattan Bank Bournemouth, UK neil.truby@chase.com ntruby@netcomuk.co.uk