Re: On-Line 7 Performance

Rudy Fernandes wrote: > > In article <331606A3.1EAB@iap.net.au>, > Andrew Mercer <amercer@iap.net.au> wrote: > >We too are having performance problems similar to other postings in this > >newsgroup. I suppose it is the nature of newsgroups that only problems > >are posted, but are there any sites that are happy with On-Line DSA. > > Yes, here's one! > > We have recently migrated from SE 5.0 to ONLINE 7.20 with no change to > our hardware. > > After some initial hiccups, performance under ONLINE is equal to or better > than under SE (Index builds under ONLINE are phenomenally fast). > > During the initial period, performance of ONLINE was as low as 30-35% of > SE. I've concluded that the following parameters were significant. > > BUFFERS keep at about 25% of Physical memory > RESIDENT 0> DBSPACETEMP pointed to 2 temporary dbspaces > MAX_PDQPRIORITY 0 > OPTCOMPIND 0> PHYSDBS separate disk. [Logical logs, Data and Physical log are each > on separate disks (Data spread on 2 disks)] > > In case checkpoints are too long (during which the system may appear to hang), > you may want to look at the following 2 parameters > > LRU_MAX_DIRTY > LRU_MIN_DIRTY> > At our site, we have brought them down from the default 60 and 50 to 2 and 1. > HTH > > ---------------------- > Rudy Fernandes > GIC, Kuwait > ---------------------- I would broadly endorse your settings, although I have my logs, phys and logical, in one dbspace. I'm interested in your having RESIDENT set to 0. Informix Tech Support recommended to me that it should be set to 1 if it has no significant effect on the paging rate. What are your, and others' experiences? Neil Truby Chase Manhattan Bank Bournemouth, UK