Reader Feedback and Insights: Frightened by the Midrange Guru

Hey, Ted:

In your tech tip "How Dynamic Is OPNQRYF?" there is one frightening sentence:

Now that you understand what's going on, let me tell you that this is not just an OPNQRYF phenomenon. It is true of any program that opens an open data path for input. Run the RPG program by itself and you will experience the same behavior. The RPG program will get an added record if the KEYFLD value is greater than the key field values of the original three records.

A little test program shows that it is not always so, and it is a good thing, too! I adapted your program so that it does not use the RPG cycle.

Fmydata    if   e           k disk    rename(mydata   : myrec)
Fqsysprt   o    f  132        printer

D Counter         s              3  0
        c     *LOVAL        setll     mydata
c                   read      mydata
c                   dow       not %eof

C                   eval      Counter = Counter + 1
C                   if        Counter = 1
C     'Add rec now' dsply
C                   endif

c                   except    detail

c                   read      mydata
c                   enddo
    
c                   eval      *inlr = *ON
    
Oqsysprt   e            detail      1
O                       counter       4
O                       keyfld           +0001     
O                       datafld          +0001     

--Jan

I'm sorry, Jan. I didn't mean to frighten you!

By using the SETLL op code, you changed the file to random access, so the system doesn't buffer the input.

Thanks for writing!

--Ted

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