Re: Oracle for Multi-Processor

Andrew Liu wrote in message <70m2to$40$1_at_ocean.cup.hp.com>...
>Hi,
>Does Oracle need special patch or version to support multi-processor host ?

Not as far as I'm aware of. IMO you don't need -any- patches to make use of a multiprocessing SMP machine.

If the application is multithreading and the first CPU is peaking at 100%, then the operating system should run any new threads (or processes) on the 2nd CPU.

>I have a PC server running WindowsNT 4.0 with 4 CPU, and I have installed
>the Orcale server 7.3.3 on the host. The result is that Oracle would
utilize
>one of the CPU only, instead of the 4 CPUs.

Once again, I don't think it's up to the software to "use all the CPU's". That is the task of the operating system. It handles process scheduling and execution and it should decide what to run where.

There's an exception to that of course. On some Unix systems there's an API call that you can make to bind your process to a specific CPU. However, this is not a good idea IMO as the kernel should handle CPU load balancing and not the application.

>I monitored this situation on
>Task Manager.

Task manager? Is that part of that of Enterprise Manager? Never touched Enterprise Manager myself as there a much better tools available IMHO. Anyway, if you want to monitor CPU usage you must do it via NT's Performance Monitor.

>Why ? Will Parallel Query Server improve the situation ?

Yes. SMP can be explained as a truck. A single CPU gives you a truck that can go let's say 120km/h and can carry 5 tons. Adding more CPUs will not make the truck go faster - it simply increases the load that the truck can carry at 120km/h. If you want to make the truck go faster, then you will have to upgrade the CPU(s) to a faster CPU(s).

OK, now we have with 4 CPUs and we're cruising down the motorway at 120km/h with a sign that says "I can carry 20 tons" and listening to the Beach Boys's Still Cruisin. How do you increase performance of software? This is where multithreading becomes important.

Let's say a single process places a 0.5 ton load on our truck. But we still only go a 120km/h. The only way for that process to perform better is to break up the work it needs to do into multiple processes. Now let's say it breaks up into 20 processes. We're now carrying 10 tons of load, we're still going down the highway at 120km/h, but we now have 20 processes doing the work of a single process.

This is a bit of a simplistic explanation, but hopefully you'll get the idea of how multiprocessing works.

>How to build up the parallel query server for multi-processor machine ?

You need to install this option when you're installing Oracle Server. I think you may also need a license for using it. Not sure though. IMHO it should be a standard Oracle Server feature.

regards,
Billy Received on Thu Oct 22 1998 - 02:30:22 CDT