Re: binding Oracle or Sybase

Reply emailed to author and posted.

Doug,

    Binding to either CPUs or memory areas, assuming you can with AIX, won't solve your problem which can best be described as:

    "10# of s*^t in a 5# bag"

    AIX is very solid, but when you run out of paging space or out of space in the root directory you can have problems. I suspect that if you investigate you will find that your system is out of paging space so you have applications stepping on each other because sufficient system resources haven't been allocated.

     Our local IBM technical contact told me that when running Oracle it is better to use a smaller SGA and have Oracle page rather than have AIX page. I suspect this is because AIX will blindly page based on LRU while Oracle is a bit smarter when comes to deciding what to flush.

    Since your management won't let you buy more memory you will have to ask them to choose between poorer performance or occasional failures of important jobs.

    If the are willing to live with poorer performance reduce the SGA size and the Sybase equivalent to the point where AIX stops paging (and just to be on the safe side increase the paging space for AIX).

    If they are willing to live with the occasional failure of an important job all you have to do is increase the paging space and (unless an agnostic) pray.

regards
Jerry Gitomer

Doug Cowles wrote in message <37A9D481.64FD6441_at_bigfoot.com>...
>We have a problem in that we run Oracle and Sybase on the same
box
>with supposedly 3GB of physical memory, although using the AIX
monitor
>commands only cites about 2.5GB. The shared pool for Oracle was
about
>1 G, and the equivalent memory structures for Sybase were about
1.5GB.
>(effectively using the entire physical memory). There are about
6GB of
>paged
>memory, but we're getting a lot of swapping lately. I reduced
the
>block buffers
>by about 1/4, (which in my case frees up 400MB), in hopes that
the users
>
>wouldn't be affected, but my question is about binding. Someone
>suggested that
>we bind Sybase processes to either CPU's or particular memory
areas,
>and/or
>do the same thing with Oracle. Recently, we had an important
job fail
>we believe
>due to the shortage of memory. Does anyone have any experience
binding
>to
>either CPU and / or memory with 2 disparate databases on the
system? We
>have
>another person on the account who is firmly against it, think
the OS
>should do it's
>thing. (Clearly, buying more memory would be nice..but not
currently an
>option).
>We are running on AIX 4.3 with Oracle 8.0.5 and Sybase 11.x
something.
>
>- Dc.
>
Received on Fri Aug 06 1999 - 09:33:30 CDT