Tuning RA for DSS on IDS7.30

Looking for information pertaining to RA_PAGES & RA_THRESHOLD onconfig parameters in a DSS only IDS7.30 UNIX environment. Last week we modified our onconfig parameters as follows: RA_PAGES from 20 to 128 RA_THRESHOLD from 10 to 120 After the change, I found that a query that would take 15 minutes is now running in 10 minutes, being that I got such a performance increase we decided to raise the RA parameters even higher: RA_PAGES from 128 to 256 RA_THRESHOLD from 120 to 240 This second change made little if any change to the query. Does anyone know what the range for these parameters are and/or any recommendations? TIA, John E. Porcello, Jr., ICP, MCSE Corporate DBA Kaman Corporation jep-corp@kaman.com My views and opinions may not reflect those of Kaman Corporation.

Run onstat -p and look at the read-cache and write-cache percentages over a typical load period. Also look at the RA usage values reported and calculate the RA Usage Ratio: RA-pgsused / (ixda-RA + idx_RA + da-RA) * 100 This ratio should be VERY close to 100 (like I get 99.498 on one system). Increase or decrease the parameters for RA until this is nearly 100. At the same time monitor the cache %s, excessive RA will degrade cache performance. If cache performance suffers, increase the number of buffers or decrease the RA parameters. BTW unless your disk farm is very slow you should get the same performance boost with lower threshold values but keeping the RA_PAGES. Threshold too high is usually seen in a small usage ratio. Art S. Kagel "Porcello, John" wrote: > > Looking for information pertaining to RA_PAGES & RA_THRESHOLD onconfig > parameters in a DSS only IDS7.30 UNIX environment. > > Last week we modified our onconfig parameters as follows: > RA_PAGES from 20 to 128 > RA_THRESHOLD from 10 to 120> > After the change, I found that a query that would take 15 minutes is now > running in 10 minutes, being that I got such a performance increase we > decided to raise the RA parameters even higher: > RA_PAGES from 128 to 256 > RA_THRESHOLD from 120 to 240> > This second change made little if any change to the query. Does anyone know > what the range for these parameters are and/or any recommendations? > > TIA, > John E. Porcello, Jr., ICP, MCSE > Corporate DBA > Kaman Corporation > jep-corp@kaman.com > > My views and opinions may not reflect those of Kaman Corporation.