Tuning Shared Buffers

Does any one have a rule of thumb for determining the size of BUFFERS in the ONCONFIG file? We have 512 megs of memory and about 75 concurrent users. An Informix consultant said we should set it to 20 megs but I feel that is too small. Does 150 megs sound appropriate? (2 megs per user).... And thanks for the help on the upgrading from 4.1.2 to 7.2.4.... We're running more test today. Valerie H. Webber Valerie.H.Webber@m1.irs.gov 704-569-1002 x107

Webber Valerie H wrote: > > Does any one have a rule of thumb for determining the size of BUFFERS in the > ONCONFIG file? We have 512 megs of memory and about 75 concurrent users. > > An Informix consultant said we should set it to 20 megs but I feel that is > too small. > > Does 150 megs sound appropriate? (2 megs per user).... > > And thanks for the help on the upgrading from 4.1.2 to 7.2.4.... We're > running more test today. You have to determine your active dataset size. What is the average and maximum number of records likely to be access during a given time period and how long it the duration of any particular active dataset. For example if all 75 users are looking at current transactions at various stages of processing (ie order entry, order processing, credit verification, order picking, packing, shipping) the active set may correspond to the number of new order begun during the time it takes to process the first order since after that the orders begin to drop off at the same rate they are being added to the active dataset. Art S. Kagel