Re: Read Ahead Pages, etc.

Posted in 1998

Andrew Lawrenson — Thu, 14 May 1998 16:42:29 +0100 — source: Informix-list mailing list archive (1991-1998)

Is there any optimum upper limit for the values of RA_PAGES and RA_THRESHOLD? I've bumped mine up from the defaults of 4/2 to 64/16, and I'm still at 99.9% pages used. How high should I go? Should I just keep going until the percentages fall? Andrew Lawrenson david.ashby@workcover.nsw.gov.au wrote in message <6jdem8$49r$1@news.xmission.com>... > > Dianne, > The calculation is: > ixda-RA + idx-Ra + da-RA > If the result is significantly lower than RA-pgused then the read > ahead parameter is set high (you are reading more pages than you > need). I try to keep the value between 5% to 10%. If the value is > under 5% the read ahead is set low. > > Regards > David Ashby - Remove nospam. from address when replying by email -