Re: DOW vs DOU

["Greg Thielen" <gregt@xxxxxxxx>]

On 30 May 97 05:14 GMT, Kahn, David wrote:

>Incidentally, any particular reason for preferring an initial SETLL followed 
>by READE over a single CHAIN?

Dave,

I was meaning to comment on your chain/doweq ths first time I saw it,
but now that you ask the question, I'll put in my $.02.

I am assuming that we pretty much agree that the clarity of the code
is more important than shaving a few nanoseconds off of run time. 
Given that, IMHO, the CHAIN opcode _implies_ a one-time single record
"read" -- even though followed by a DOWEQ.  SETLL/READE OTOH implies
that a number of like-keyed records are going to be processed.  I
realize that in your shop that CHAIN/DOWEQ may be a "standard" and
quickly recognized, but I've never seen it in any production code
I've worked on (and I've seen a lot of different styles).  This is
something I would look at for a few seconds and think sarcastically,
"cute".  There was also a time (pre-AS/400 and even S/38 I think)
when CHAIN didn't set the file pointer as it does now.  You _had_ to
use SETLL/READ.





-------------------------
Greg Thielen
Innovative Systems Design
gregt@isda.com
http://www.isda.com


* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* This is the Midrange System Mailing List!  To submit a new message,   *
* send your mail to "MIDRANGE-L@midrange.com".  To unsubscribe from     *
* this list send email to MAJORDOMO@midrange.com and specify            *
* 'unsubscribe MIDRANGE-L' in the body of your message.  Questions      *
* should be directed to the list owner / operator: david@midrange.com   *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *