Re: Can an open list , from the the QGYOLxxx APIs, be resorted?

A new sort sequence means opening a new list. I seem to recall though that you were planning to write the results to a database file. A logical file (or the QLG* sort APIs which work with both files and storage buffers) could take care of the sorting fairly easy.

As for caches, I believe (but did not bother confirming...) that Joe was refering to List APIs rather than Open List. I suspect the performance improvement is due to general storage management -- the user space has been recently touched (and possibly extennded) and the second run through the list does not incur as much paging as the original run (and was possibly already at a more appropriate size). Likewise both the List and Open List may get some benefit from some of the spool information already being in storage due to the earlier run.

Open List, in addition to the potential cache benefit, also has the advantage that you can have the list being generated in a server job while your job is processing returned (already processed) entries. This parallelism is done under the covers for you. NOTE though that if you request that sorted results be returned then you turn off any of this parallelism. The Open List API can't return anything to you until it's built the entire list as it doesn't "know" if the last entry to be examined just happens to be number one in the sort sequence you want...

Bruce

----- Original Message ----- From: "Charles Wilt" <charles.wilt@xxxxxxxxx>
To: "Midrange Systems Technical Discussion" <midrange-l@xxxxxxxxxxxx>
Sent: Thursday, May 07, 2009 3:03 PM
Subject: Can an open list , from the the QGYOLxxx APIs, be resorted?

I'm looking at the Open List of Spool Files (QGYOLSPL) API.

I see where you can specify sorting for the list.

My question, once the list is open (and fully built) is there anyway
to resort it in a different manner without closing and reopening a new
list?

I don't see any likely APIs on the Process Open List page here:
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/apis/misc1b.htm

But I thought I'd ask.

In my original post about WRKOUTQ vs. QUSLSPL vs. QGYOLSPL, Joe Pluta
mentioned that the Open List APIs do caching behind the scenes, so
perhaps closing and opening a new list with the same filter but a
different sort wouldn't be as costly as opening the list originally?

Thanks!

Charles Wilt
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/midrange-l.