RE: CHAIN Versus SETLL and READ When Data Needed

Yes.  If chain failed, the file pointer will be lost.  
I was replying about Steve's email regarding it clears the buffer if
chain failed.  I don't believe that is true.  If chain failed, all data
in the program remain the same, which is why I think using setll and
then read will not have any performance gain.  I think it will make it
run slower (Not to mention ugly coding :)).



-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Marvin Radding
Sent: Wednesday, February 28, 2007 3:44 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: RE: CHAIN Versus SETLL and READ When Data Needed

message: 1
date: Wed, 28 Feb 2007 15:04:47 -0600
from: "Lim Hock-Chai" <Lim.Hock-Chai@xxxxxxxxxxxxxxx>
subject: RE: CHAIN Versus SETLL and READ When Data Needed

AFAIK, chain will not clear any data in the program when not found.
With that say, I think chain is faster.  Since setll and read require 
two trips.  If chain is not found, it would be like setll.

From the manual:

When the CHAIN operation is successful, the file specified in name is
positioned such that a subsequent read operation retrieves the record
logically following or preceding the retrieved record. When the CHAIN
operation is not completed successfully (for example, an error occurs or
no record is found), the file specified in name must be repositioned
(for example, by a CHAIN or SETLL operation) before a subsequent read
operation can be done on that file.


Just so no one is lead astray, if a CHAIN fails, the pointer is
undefined and any read operation will results in an error.

Marvin


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