Re: Informix Perf Question

Wayne Lyle (wlyle@PROBLEM_WITH_INEWS_DOMAIN_FILE) wrote: : I have setup an informix database on a Sparc10. 5.00.UC3. The : configuration is generally the same as other servers I have but it runs : different applications. I have noticed that this server generally has : 0% - 30% cache reads and 80% - 95% cache writes. On the other servers : the cache read and write range from the high 80% to 90+%. Is it possible : that the applicationbs software is negatively impacting the cache %?? : The database is spread across 5 disks over two controllers. It is : mirrored and has buffered logging. The configuration is listed below. Any : ideas would be greatly appreciated. Wayne, It looks like your system is fairly well configured. When are you seeing the poor hit rates? If it's just after startup, you may be showing bad numbers as the buffers are filling. Run it for a day and then tbstat -z and see how the numbers look. What's your tbstat -p look like? Are you seeing any performance degradation, or is it just the low hit rates that worry you. 30% is WAY too low. Is the system swapping? Post more info, this is an interesting problem. Joe -- --------------------------------------------------------------------------- Joe Lumbley(jlumbley@netcom.com) Dallas, Texas author of: INFORMIX DBA Survival Guide from Prentice-Hall/Informix Press ISBN 0-13-124314-4 (12431-3) Now available in bookstores orders: orders@prenhall.com (515) 284-6761 fax (515) 284-2607 ----------------------------------------------------------------------------