memory sort and disk sort

I check the sysprofile table and find there are 700 times disk sort, I think it is lack of sort memory. I want to turn all the disk sort into the memory sort ,but how can I malloc more sort memory for informix? Now my shmvirtsize is 800000(800M) Another question is: my server run with 99% read cache hits but just 75% write cache hits, how can I mprove the write cache hits ? Thanks -- Posted via http://dbforums.com

On Thu, 23 Oct 2003 03:15:11 -0400, dusong wrote: Version and platform information is important! For example 7.31UD4 (and IB 9.30) and later improved the memory sorting algorithms which reduced the number of sorts that go to disk. Also using PDQPRIORITY and PSORT_NPROCS will improve sort efficiency and memory usage by dividing up the sort job into smaller sub-sorts which are merged later. > I check the sysprofile table and find there are 700 times disk sort, > > I think it is lack of sort memory. I want to turn all the disk sort into the > memory sort ,but how can I malloc more sort memory for informix? > > Now my shmvirtsize is 800000(800M) > > > > Another question is: Without more information one cannot answer this one. It could be too much read ahead, too few BUFFERS, LRU_MAX/MIN_DIRTY too low, or just an application load that is doing massive inserts or updating only one or two rows on a page but touching most pages. Post your ONCONFIG file, onstat -p, onstat -P (top 15 and bottom 10 lines only are needed and any partnums with lots of pages), the time since the system stats were last zero'd (onstat -z) if after startup, and a description of your disk farm (ie singleton drives, RAIDx, SAN, etc.) and we'll see what we can see. Art S. Kagel > my server run with 99% read cache hits but just 75% write cache hits, > > how can I mprove the write cache hits ? > > > > > > > Thanks > > > -- > Posted via http://dbforums.com