Re: sybase system 10 limitation of 4 processors ?

In article <lchutsonD7K3zE.H7p@netcom.com>, lchutson@netcom.com (Lawrence Hutson) wrote: > What exactly do you mean support for more than one processor? I have > heard this talk before, but I was under the same conclusion as > Dr. Chen that most DBMS are IO bound. Whether a particular DBMS is I/O bound depends on the application. Some applications will access a small enough set of data that they will do very little I/O after rampup, and thus will be CPU bound. On the other hand, other applications will access a large enough set of data to make it impossible or impractical to cache - these types of applications can be I/O bound if there are not enough disks available to handle the I/O required. However, if you can configure and use enough disks, then even applications which access enormous amounts of data can be CPU bound. > > What support are these DBMS claiming for multi processors. Are we > talking about being able to assign process to a processor? I think Not. > You have to have OS support for that. Correct ? The support the DBMS claim for multi processors, in the context of this thread, refers to the ability to utilize all of the CPUs in an SMP system, i.e. a computer with multiple CPUs that share access to the same set of memory, the same set of disks, and which runs a single copy of the OS. Sybase has been rumoured to have internal architectural limitations which prevent it from utilizing more than 4 CPUs in an SMP. Oracle and Informix have not suffered from the same slings and arrows of doubt as their scalability on SMP's, but neither (to my knowledge) has proven scalability beyond about 20 CPUs, though I know they are both working on it... Kevin J > > > Lawrence C. Hutson, Consultant > HCI International > > ahl@cc.bellcore.com wrote: ~~~~~~~~~~~~~~~ emergent: the parallel systems experts ~~~~~~~~~~~~~~~ Kevin Jernigan 415-567-8915 (p) emergent corporation 415-265-0785 (c) kjerniga@emergent.com http://www.emergent.com 415-367-6414 (f)