RE: Restoring ontape archives between 32 bit and 64 bit versions
> correct
While it may be perfectly true for Ben Thompson's scenario,
it seems a bit too "over-generalized" a statement.
The reason being, that not all the (shared) memory used by
IDS is for the buffer pool. There are other uses, e.g. for the
socalled "Decision Support" operations (check the "DS_..."
parameters in your onconfig file). Or there are "read ahead"
and "light scans" which can bypass the buffer pool but still
utilize memory.
To know whether a certain scenario (combination of IDS
and the client application's types of queries) can make use
of any of these or not requires much more detailed knowledge
of the application. Sometimes only trying reveals insight.
Since this really is a complicated matter with many factors
to consider, performance tuning often is a task for on-site
consulting. I may have said this before ... :)
Of course if you have been satisfied by the performance
of your system all the time and you never got a message
in online log file about not being able to allocate more
memory, then you can calmly say you probably don't need
more.
Besides, it is usually the case that tuning on the client
application side produces much greater performance
benefits than tuning on the server side. But then again
client application tuning is not always possible ...
Regards,
Martin
--
Martin Fuerderer
IBM Informix Development Munich, Germany
Information Management
owner-informix-list@iiug.org wrote on 16.02.2005 20:36:11:
> correct
>
> > -----Original Message-----
> > From: owner-informix-list@iiug.org
> > [mailto:owner-informix-list@iiug.org] On Behalf Of Ben Thompson
> > Sent: Wednesday, 16 February 2005 10:14 p.m.
> > To: informix-list@iiug.org
> > Subject: Re: Restoring ontape archives between 32 bit and 64
> > bit versions
> >
> > Claus Samuelsen wrote:
> > > Ben Thompson wrote:
> > >
> > >> On a related note, and sorry if this is a "how long is a piece of
> > >> string" type question, what sort of performance improvement can I
> > >> expect by moving to a 64 bit kernel running a 64 bit
> > version of IDS
> > >> over 32 bit versions on the same hardware?
> > >
> > >
> > > If you have memory on the machines that you cannot allocate with 32
> > > bit systems, then you can get better performance with 64
> > bit version,
> > > because you can setup much larger buffers.
> >
> > We don't have a problem with not being able to allocate
> > sufficient BUFFERS. Does this mean that for us there are no benefits?
> >
> > Ben.
> >
>
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