RE: Write cache rate

Malcolm confessed: > I have often wondered if there are any detrimental effects (other than > excessive OS paging and/or swapping) of having "too many buffers". The major detrimental effect I have seen from too many buffers is not having enough memory for the rest of the server's needs. I could start a lecture on internals, now, but my management would probably prefer I earn my salary, so I will point those interested and uninformed to the IBM Informix Dynamic Server Administrator's Guide chapter on shared memory: http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.admin.doc/admin264.htm Too many buffers can also lead to longer checkpoints, but that can usually be tuned with other parameters. Knowing Malcolm, I don't think he needs this information, anyway. Your setup sounds like ours, Malcolm: lots of in and out data entry during the day, big batch reports and some large loads at night. As I said, we have usually found that we need to over allocate buffers, beyond the normal 20-25% of physical memory described in the manuals. This does not hurt us during the day, so long as the box has plenty of memory. We try to make certain our customers have more physical memory than they will ordinarily use, in order to avoid the disk swapping, which we have seen become catastrophic. So, from our experience, "too many buffers" does not seem to be a problem, given that everything else is adjusted, accordingly. I would love to hear the results of your testing, whether it matches or not. Sincerely, Christopher Coleman Steering Committee President Kansas City Informix Users Group www.iiug.org/kciug Database Analyst Pharmacy Division Mediware Information Systems, Inc. sending to informix-list

Christopher Coleman wrote: <snip> > Too many buffers can also lead to longer checkpoints, but that can usually be tuned with other parameters. <snip> Shouldn't do anymore ... http://tinyurl.com/cxu47

"TBP" <TheBigPotato@NotHere.Co.Uk> wrote in message news:Beykf.7961$xP2.6488@newsfe2-gui.ntli.net... > Christopher Coleman wrote: > > <snip> >> Too many buffers can also lead to longer checkpoints, but that can >> usually be tuned with other parameters. > <snip> > > Shouldn't do anymore ... > > http://tinyurl.com/cxu47 How do you get to the search facility above that URL?

Neil Truby wrote: > "TBP" <TheBigPotato@NotHere.Co.Uk> wrote in message > news:Beykf.7961$xP2.6488@newsfe2-gui.ntli.net... > >>Christopher Coleman wrote: >> >><snip> >> >>>Too many buffers can also lead to longer checkpoints, but that can >>>usually be tuned with other parameters. >> >><snip> >> >>Shouldn't do anymore ... >> >>http://tinyurl.com/cxu47 > > > > > How do you get to the search facility above that URL? > > Do you mean here? http://www-306.ibm.com/software/data/informix/ids/support/