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Please don't bust me for copyright violations but from the November 1998, Volume 1, Number 1 of AS/400 Experts Journal in an article by Skip Marchesani (definitely Godlike when it comes to DB2/400): He talked about using the Predictive Query Governor to determine which index to build and by following it's recommendation to build a logical file saved a 7 to 1 runtime in one example and a 12 to 1 in another. Now for the quote: Access paths are a good thing! There is a myth in the AS/400 community that is no longer true. That is: Access paths (logical files) on a file are resource intensive, have a negative impact on performance, and should only be used where absolutely necessary. This is no longer true in today's environment on the AS/400! This myth stems from the S/38 and was the guideline that IBM was giving customers at that time. The Rochester development lab began to change the algorithms for access path maintenance in Version 2 of OS/400 and finished the task in V3R1. Access paths (logical files) are no longer the resource/performance hog they used to be on the S/38. Rob Berendt ================== "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin David Gibbs <dgibbs@mks.com> To: "'midrange-l@midrange.com'" <midrange-l@midrange.com> Sent by: cc: midrange-l-admin@mi Fax to: drange.com Subject: RE: What is really the level check 11/14/2001 11:23 AM Please respond to midrange-l This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. -- [ Picked text/plain from multipart/alternative ] > We have got a CL program running at the end of day, this > program creates a > logical file from a dds stored in a source library and calls > a number of > RPG programs and then it deletes the file at the end. Why delete the logical? Unless the overhead of maintaining the index is extraordinary, I would recommend you just leave it out there and save the rebuild time. david _______________________________________________ This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@midrange.com To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/cgi-bin/listinfo/midrange-l or email: MIDRANGE-L-request@midrange.com Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l.
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