Re: Calling Program information

[Charles Wilt <charles.wilt@xxxxxxxxx>]

Just to be clear,

Journalling + commitment control + "Soft Commit" = awesome :)
Journalling + commitment control = good
Journalling by itself = can be ok, but the performance (by default) it
is definitely noticeable on batch processes even on today's
processors.  Mainly because processor doesn't matter, disk speed is
the big factor.

I say "by default" because IBM has a LPP that you can pay for to
improve the situation.  That allows you to turn on "journal caching"
when you don't use commitment control.

Note that the "Soft Commit" option mentioned is new to v5r4 and brings
the benefits of journal caching to smaller commit transactions.
Standard journalling + commitment control performs best the closer you
can get your transactions to 128KB of data.

I highly reccommend the redbook "Striving for Optimal Journal
Performance on DB2 Universal Database for iSeries"
http://www.redbooks.ibm.com/abstracts/sg246286.html?Open

And the technote "Soft Commit: Worth a Try on IBM i5/OS V5R4"
http://www.redbooks.ibm.com/abstracts/tips0623.html

HTH,
Charles


On Thu, Mar 5, 2009 at 1:18 PM, Peter Connell
<Peter.Connell@xxxxxxxxxxxxxxxxx> wrote:
> We journal everthing to be sent to a DR box.
> Even with everything journalled the performance is very good with today's processors.
> For 1 file. You won't even notice it.
> You can restrict the size of that the journal will reach before the system detaches it and starts another and have some job remove detached journals.
>
> Peter