Re: Setll vs. chain

[STEVEN_J_RYAN.NDOA@xxxxxxxxxxxxxxxxx]

Have you considered a Join Logical between your Master File & your Formula
File, and using that in place of your Master File in your program?

Because the join is restricted to those records with common information
(e.g. Part number in both Master File & Formula file), you would ensure you
only read the 1000 records of your Master File that had a Formula file
equivalent.  The other 299,000+ records would be ignored by the Logical,
and so wouldn't be processed by the program.




"Carl Pitcher" <cpitcher@roadrunner.nf.net> on 10/02/2000 09:36:47

Please respond to RPG400-L@midrange.com

To:   RPG400-L@midrange.com
cc:    (bcc: STEVEN J RYAN/DIAU)

Subject:  Setll vs. chain




We have a report program that processes a master file of 300,000+ records
which runs ever so slow.  Each record chains to a formula file to see if a
formula exists and does some calcs. Out of the total master file, there
would be no more than 1000 successful hits on the formula file.  Before I
go
ripping this code apart (and converting it to RPGIV in the process), my
expectation is that if I change the CHAIN to a SETLL and then chain on a
successful hit that it should improve the performance considerably.  Am I
wrong in assuming that SETLL will just look at the "index" which should be
in memory as opposed to CHAIN which most often requires an access to disk
to
retrieve the record? TIA.
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