Re: *Max4GB or *Max1TB

[Vernon Hamberg <vhamberg@xxxxxxxxxxx>]

Hi Paul

I searched the iSeries support site for ACCPTHSIZ and found a couple 
things. One has to do with access path sharing--

In R410, the default for Access path size (ACCPTHSIZ) changed to 
*MAX1TB rather than *MAX4GB on the CRTLF and CRTPF commands and in 
the SQL CREATE INDEX statement. Most existing access paths have an 
attribute of *MAX4GB. These access paths cannot be shared by access 
paths with an attribute of *MAX1TB. For access path sharing to occur, 
change existing access paths to ACCPTHSIZ(*MAX1TB) or specify 
ACCPTHSIZ(*MAX4GB) on the new access paths.

The other is from "The System Administrator's Companion to AS/400 
Availability and Recovery"
Redbook http://www.redbooks.ibm.com/redbooks/pdfs/sg242161.pdf 
section 16.14, where it says the 4-byte index is supposed to 
circumvent seize locks. It also says not to mix the 2 kinds of indexes.

HTH
Vern

At 10:16 AM 4/8/2006, you wrote:

> I've got a client experiencing performance problems with his software
> package. Many of the files have a huge number of logicals built over them
> for various purposes. One has over 250 logicals and joined logicals. All
> of the files are defined as having an acces path size of 4GB.
>
> This system is also being hit with lots of ODBC requests that were
> permitted to be built by the previous IT manager (windoze bigot).
>
> I know how to throttle back the ODBC impact, but should I change the acces
> path size to 1TB for just the logicals or both the physical and its
> associated logicals to improve the overall performance?
>
> Thanks
> --
>
> Paul Nelson
> Arbor Solutions, Inc.
> 708-670-6978  Cell
> pnelson@xxxxxxxxxx
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