RE: buffering -- MI400

No pain, no gain.  Except for the System/38-to-RISC hacking, I think we have
the right stuff here.  Create an RPG program to use as a stalking horse for
offsets and I think we have it.  The block size settings are made as
structures tagged onto the end of the UFCB before QDMCOPEN is called.  The
trick is that the data structures are documented in the data areas manual on
the override structure and not documented on the UFCB structure.  It took me
half an hour to remember that.  I'm getting old and stupid.

In 1984, my first MI program was an MI compiler.  It loaded data from a file
into a user space then called the PRM.  My version used blocked record IO
and supported conditional nested include files, like C.  It was fairly fast
... :)  I never used more than one level of include after that but the
education was fun.  It t'were a bit harder to write MI in those days that it
is now - no documentation except the PRPQ manual and one had to sign license
and confidentiality agreements to get more information.  My "assistance"
contact was a private arrangement - he retired from IBM just last April.

Richard Jackson
mailto:richardjackson@richardjackson.net
http://www.richardjacksonltd.com
Voice: 1 (303) 808-8058
Fax:   1 (303) 663-4325

-|-----Original Message-----
-|From: owner-mi400@midrange.com [mailto:owner-mi400@midrange.com]On
-|Behalf Of Don
-|Sent: Saturday, October 07, 2000 9:15 PM
-|To: MI400 List
-|Subject: Re: buffering
-|
-|
-|
-|
-|Leif,
-|
-|Out of curiosity, why are you doing all this torture?  :)
-|
-|Don
-|
-|On Sat, 7 Oct 2000, Leif Svalgaard wrote:
-|
-|> As part of my ongoing investigation of sorting large files,
-|> I'm reading the files myself into storage to sort them there.
-|> I have a question about buffering. It doesn't make sense
-|> that it takes 15 minutes to read 10Mb (1,000,000 records
-|> of 10 bytes each), so I must not have the right buffering
-|> set up. What controls that? I was under the (mistaken ?)
-|> impression that suitable buffering was done by OS/400
-|> so I don't have to worry about it. If that's the case, it
-|> is doing a poor job. More likely, I need to do something
-|> to get better buffering. What?
-|>
-|> Leif Svalgaard
-|>
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