Re: PDQ Advice Please

From: "Tony Flaherty" <aef@mfs.misys.co.uk> > >Hp-Ux 10.20 >IDS 7.30.UC7 > >We have a OLTP set-up with occasional large queries/updates running during >the day. I've not paid that much attention to the PDQ settings previously >:o/ I thought it was disabled. However I've started reading up on it in >the >hopes that I can use it to reduce the impact of the bigger update programs >that are run. > >My current ONCONFIG params for PDQ are; > >MAX_PDQPRIORITY 100 # Maximum allowed pdqpriority >DS_MAX_QUERIES # Maximum number of decision support>queries >DS_TOTAL_MEMORY # Decision support memory (Kbytes) >DS_MAX_SCANS 1048576 # Maximum number of decision support scans> >NOTE that there is no entry for PDQPRIORITY, TFM indicates that there >should be an entry for this and it should be zero. Is this the default >since there isn't one, is my manual out of date or is my instance >configured >incorrectly? PDQPRIORITY is now controlled with an SQL statement or an environment variable. >A MAX_PDQPRIORITY of 100 appears to be bad! is it? From my understanding >of >TFM I would of thought if PDQ was active on my machine I would be having >real problems with the above settings. Nope, it means that you are prepared to allocate 100 % of PDQPRIORITY % of PDQ resources to any given PDQ query. >If I set PDQPRIORITY to zero in the ONCONFIG and then assign values to the >other PDQ parameters, do they have any effect? I think it will ignore PDQPRIORITY in the onconfig. >Also, am I correct in saying that I can modify my heavy process >(Informix-4GL) so that it issues a SET PDQPRIORITY stmnt to reduce its >impact on the system. If so can you recommend a % to use? or indeed any >other methods of reducing its impact, I was toying with the rather >inelegant >idea of placing a SLEEP 1 in an appropriate place :o(. I don't think 4GL supports that syntax, I'd go for setting the PDQPRIORITY environment variable. But there is a fundamental problem here: if your 4GL is a record-oriented, line-at-a-time kind of program, PDQ probably won't help. :) ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

Obnoxio The Clown wrote: [cutting > >Also, am I correct in saying that I can modify my heavy process > >(Informix-4GL) so that it issues a SET PDQPRIORITY stmnt to reduce its > >impact on the system. If so can you recommend a % to use? or indeed any > >other methods of reducing its impact, I was toying with the rather > >inelegant > >idea of placing a SLEEP 1 in an appropriate place :o(. > > I don't think 4GL supports that syntax, I'd go for setting the PDQPRIORITY > environment variable. AFAIK it does > > But there is a fundamental problem here: if your 4GL is a record-oriented, > line-at-a-time kind of program, PDQ probably won't help. :) Very true -- Paul Watson # WF Software Ltd # You are only young once Tel: +44 1436 674729 # but you can be immature Fax: +44 1436 678693 # for ever www.wfsoftware.com #