Access Path Size ACCPTHSIZ

nanda

Member
Does anyone have any experience of changing the ACCPTHSIZ parameter from the
default *MAX4GB to *MAX1TB?

In theory this could improve performance and seems ot be the recommendation
of IBM. However it would appear that there might be a downside as far as
dasd and memory requirements are concerned.

Any experience - positive or otherwise - welcomed!

Regards
Nanda
 
Nanda,

I HAD to change the ACCPTHSIZ parameter on some files and their logicals to
the larger index size, due to performance degradation. We have a couple of
files in the 25 million record range, and when multiple WW's were building
indexes over the files, while concurrent interactive users were updating
those files, the interactive users performance would drop measurably. At
times, they appeared to be locked up, it was so slow.

I have not seen a big difference in size as a result of these changes.
However, I have a 400 G system, so I do have a lot of space to work with.

Chuck

----- Original Message -----
From: "nanda" <[email protected]>
To: <[email protected]>
Sent: Wednesday, November 22, 2000 4:35 AM
Subject: Access Path Size ACCPTHSIZ ~~0:1550


> Does anyone have any experience of changing the ACCPTHSIZ parameter from
the
> default *MAX4GB to *MAX1TB?
>
> In theory this could improve performance and seems ot be the
recommendation
> of IBM. However it would appear that there might be a downside as far as
> dasd and memory requirements are concerned.
>
> Any experience - positive or otherwise - welcomed!
>
> Regards
> Nanda
>
>
>
>
> --------------------------
> To view this thread, visit the JDEList forum at:
>
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550
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Nanda

I have seen that set to *MAX1TB with improvements in things like query and WW.


Scott Parker
Grote Industries, LLC.
WorldSoftware Version 8.1.2 AS/400 V4R4 (soon to be V4R5)
 
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We had this situation a couple of months ago. It was not
pretty, because unbeknownst to us during our nightly billing run one of our
programs had an error and had stopped writing records to a file because it
max out the access path size. This file had a huge number of records with a
very lengthy klist. The bad think about this problem was we did not even
know the error was occurring because the program did not abnormally end the
error was monitored in the program. The only way we found out was a user
said his report was missing records. So you make want to check all your
files that are approaching the max size in advance.

Once we identified the problem, we did the same as you and
got the info from IBM. We were concerned because IBM noted that is was not
a good idea to have LF's off of the same PF to be mixed with the default
access size. If you were going to increase it should be done to all files
in the grouping. Since this file was very large with many logical files we
opted to purge records from the file, reorganize the file and rebuild the
access path(leaving the size at 4GB). The purge alone does not affect the
access path size you also need to reorganize the file. The rebuild of the
access path took over twenty hours. We are monitoring for other files that
are reaching the max and will most likely handle others in the same way.
The performance gain really did not make the call for us to change the size.

Also you may want to run it by JDE, on any upgrades are they
sending the files are the files sent with 1TB access path size or 4GB.
Hope this helps.

Thank you,
Karen Curley
Manager of Enterprise Software Development
 
I have had a number of clients that have been advised by GCS (Global
Customer Support - RL of old) to perform this task. If you have performance
problems and you have not done it then GCS will find it difficult to support
you until you have.

All clients that have made the change have noticed overall performance
improvements. If memory serves me right OS upgrades prompted the need to
change.

Adrian
----- Original Message -----
From: "nanda" <[email protected]>
To: <[email protected]>
Sent: Wednesday, November 22, 2000 9:35 AM
Subject: Access Path Size ACCPTHSIZ ~~0:1550


> Does anyone have any experience of changing the ACCPTHSIZ parameter from
the
> default *MAX4GB to *MAX1TB?
>
> In theory this could improve performance and seems ot be the
recommendation
> of IBM. However it would appear that there might be a downside as far as
> dasd and memory requirements are concerned.
>
> Any experience - positive or otherwise - welcomed!
>
> Regards
> Nanda
>
>
>
>
> --------------------------
> To view this thread, visit the JDEList forum at:
>
http://198.144.193.139/cgi-bin/wwwthreads/showflat.pl?Cat=0&Board=W&Number=1
550
> *************************************************************
> This is the JDEList World Mailing List.
> Archives and information on how to SUBSCRIBE, and
> UNSUBSCRIBE can be found at http://www.JDELIST.com
> *************************************************************
>
>
 
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