Re: IDS Features - MAX_PDQPRIORITY

On Dec 27, 4:36 pm, Dave <In4Mix...@gmail.com> wrote: > Hello, > > Aside from fragment elimination, are there any other features that are > enabled by IDS that result from setting MAX_PDQPRIORITY to 1 (or > greater)?? > > Any help would be greatly appreciated. At PDQPRIORITY 1 only fragment elimination is activated. At PDQPRIORITY 2 or greater all other parallelization features are enabled with the degree of parallelism controlled by the MAXPDQPRIORITY governor and using the resulting PDQ level as a percentage of available resources. So, if there are 24 CPU VPS and you have and effective PDQ level of 10% (PDQPRIORITY * MAXPDQPRIORTY) then you will get parallel query enabled with as many threads as required but only 2 CPU VPs running those threads. With effective PDQ level 50% you'll have up to 12 CPU VPs processing your threads. MGM memory is similarly doled out according to the number of active PDQ Queries and the PDQ level. Note that if a PDQ query cannot get access to the level of resources it requires due to competition from other PDQ queries it will wait until the required resources are available. This means that if a query is running that has requested a PDQPRIORITY of 100 it cannot run until all preexisting PDQ queries have completed and no new PDQ queries can run until it completes. They will be placed on the wait queue. Art S. Kagel > --Dave

Hi As far as I remember fragment elimination is always ON. What is activated at PDQPRIORITY of 1 is parallel scans. regards Gustavo Art S. Kagel wrote: > On Dec 27, 4:36 pm, Dave <In4Mix...@gmail.com> wrote: > >> Hello, >> >> Aside from fragment elimination, are there any other features that are >> enabled by IDS that result from setting MAX_PDQPRIORITY to 1 (or >> greater)?? >> >> Any help would be greatly appreciated. >> > > At PDQPRIORITY 1 only fragment elimination is activated. At > PDQPRIORITY 2 or greater all other parallelization features are > enabled with the degree of parallelism controlled by the > MAXPDQPRIORITY governor and using the resulting PDQ level as a > percentage of available resources. So, if there are 24 CPU VPS and > you have and effective PDQ level of 10% (PDQPRIORITY * MAXPDQPRIORTY) > then you will get parallel query enabled with as many threads as > required but only 2 CPU VPs running those threads. With effective PDQ > level 50% you'll have up to 12 CPU VPs processing your threads. MGM > memory is similarly doled out according to the number of active PDQ > Queries and the PDQ level. > > Note that if a PDQ query cannot get access to the level of resources > it requires due to competition from other PDQ queries it will wait > until the required resources are available. This means that if a > query is running that has requested a PDQPRIORITY of 100 it cannot run > until all preexisting PDQ queries have completed and no new PDQ > queries can run until it completes. They will be placed on the wait > queue. > > Art S. Kagel > > >> --Dave >> > > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list > > >