Re: Logical file access paths

This would be just a guess because "key" may mean a couple of different 
things in your post, but I wonder if the program is not doing what you 
think it is doing?

As I understand it you use a key to set the file at a particular record 
and read that record.  If the record is equal you change the key and 
update the record and then READE the next record and either set on *IN31 
or do the loop again.  But I am thinking you will almost always set on 
*IN31 as the key has just been changed?

In other words, does the program process just one record, thereby giving 
you fast response time?

_______________________
Booth Martin
boothm@earth.goddard.edu
http://www.spy.net/~booth
_______________________




Colin Thorpe <Colin@IBS-PUBLIC-SERVICES.CO.UK>
Sent by: owner-rpg400-l@midrange.com
04/12/2000 10:33 AM
Please respond to RPG400-L

 
        To:     "'RPG400-L@midrange.com'" <RPG400-L@midrange.com>
        cc: 
        Subject:        Logical file access paths



Good morning/afternoon,

I have a question regarding access paths.

When I create a logical file over a physical file containing 10,000,000
records, it takes quite some time.

This is presumably building some kind of Matrix/lookup table?

This I can understand.

So then,
Why, when I update the key to this logical in a Do loop (so attempting to
re-read the file) , does it not have to update the matrix/lookup table
(before the re-read) and therefore take a long time to complete.

ie.
KEY              SETLL                           FILE1
                 DOW                             *IN31=*OFF
KEY              READE           FILE1
                 (CHANGE KEY)
                 UPDATE                  FILE1           (move this 
records position within the logical
order)
                 ENDDO



Thanks in advance 


Colin 
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