I suppose you have at least tried to explain to those users that if they
actually tell a sort program it can use 150 GiB more storage than the
real storage on the machine that not only will they NOT get a fast sort,
but they will get an incredibly slow and expensive one because of paging
delays and paging overhead - and everything else running on the machine
for the long time it will take this to run will also see response go to
the dogs. They might not care about the latter, but some other users of
the system with more clout might.
A decent sort utility that is given a realistic amount of virtual
storage that can be kept in its working set in real storage, and which
knows that the bulk of its temporary storage is on slower external
devices can optimize circles around the abuse of the paging system these
users are requesting.
If the users can't understand that argument, you can probably expect
them to also write their own sort program and use a bubble sort - and be
surprised when it takes several years to run with that volume of data!
The task of sorting 150 GiB of data shouldn't be delegated to neophytes
that don't understand that resources have limits and that there are good
reasons why some techniques are deprecated.
J. C. Ewing
On 03/22/2011 03:41 PM, Mike Schwab wrote:
I have some users who requested 150GB of Paging packs so they could do
an in core reorg of multiple M9 volume DB2 databases, because that was
the fastest way. I told them that was too much and they needed to
specify sort work statements. They resisted and the request is
pending.
On Tue, Mar 22, 2011 at 3:21 PM, Mark Pace<[email protected]> wrote:
I assume that since it used 1792MB it has to be from above the line.
There is not a dump. The program ends nicely with an error message, not an
IBM message, that it is out of memory.
It's batch utility to massage SMF data and was not written inhouse. The SE
is talking with them now. There suggestion was to process less data. :-D
The LPAR is 4GB and I really don't know how much is to much.
I don't have a default region size, that I know of. I allow the use of
REGION=0M and don't have any exit to limit that size.
--
Joel C. Ewing, Fort Smith, AR [email protected]
Bentonville, AR [email protected]
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