Re: SQL update vs RPG/DDS update

["Gene Burns" <burns.gene@xxxxxxxxx>]

|    d mstrDS        e ds                  extname(hclmmas)
|
|    d savmstr       e ds                  extname(hclmmas) prefix(o)
|
|    d newmstr       e ds                  extname(hclmmas) prefix(n)
|

There is no indication that the chain failed for any of the users.  They are
all accessing the same record, in the file, with the same program.  There is
no commitment control on the file or in the program.

Gene

On 10/5/07, Wilt, Charles <WiltC@xxxxxxxxxx> wrote:
> Gene,
>
> Ok, with CHAIN, blocking is not a factor.  So there's something else going
> on.
>
> As Joe mentioned, on of the benefits of Single Level Store is that the
> record only exists in one
> place, when the record is written out, everybody sees the updated version
> according to the level of
> commitment control in use.  It doesn't appear that this program is using
> commitment control.  What
> about the program being used by the other user?
>
> How are NEWMSTR and SAVMSTR defined?
>
> Also, any chance the CHAIN is failing for some reason?
>
> Charles
>
> > -----Original Message-----
> > From: rpg400-l-bounces+wiltc=cintas.com@xxxxxxxxxxxx
> > [mailto:rpg400-l-bounces+wiltc=cintas.com@xxxxxxxxxxxx] On
> > Behalf Of Gene Burns
> > Sent: Friday, October 05, 2007 12:51 PM
> > To: RPG programming on the AS400 / iSeries
> > Subject: Re: SQL update vs RPG/DDS update
> >
> > CHAIN followed by UPDATE, but with an externally defined DS.
> >
> >
> >
> >      fhclmmas   uf   E           K DISK
> >
> >
> > |    d mstrDS        e ds                  extname(hclmmas)
> >
> >
> >           // get the current record from the file
> >           chain (cmyrin: cmycin) clmmas;  // loads mstrDS
> >
> >           // compare the current record in the file to the
> > original before
> >           //    making changes
> >           if savmstr = mstrDS;
> >             mstrDS = newmstr;   // set fields to new values
> >             clchgd = today;
> >             clchgt = %time();
> >             clchgu = userid;
> >             update clmmas;
> >             savmstr = mstrDS;  // update saved DS to new values
> >             origscreen = screenDS;
> >             completed = *on;
> >           else;             // file has been changed by another user
> >             unlock hclmmas;
> >             completed = *off;
> >             message = NoUpdMst + %trim(clchgu) + Retry;
> >             wrkadj = *zero;
> >             wrkadj2 = *zero;
> >             wrkadj3 = *zero;
> >           endif;
> >         else;
> >
> >
> > When the file has been updated by someone else the DS are
> > different, HCLMMAS is unlocked, and the message is
> > (supposedly) set telling the user who updated the file. The
> > CLCHGU field is in the file, but is blank at this point in
> > the program.  Checking the file shows that these fields have
> > been updated and CLCHGU is not blank.
> >
> > Perhaps the addition of the DS is what is causing this problem?
> >
> >
> > Gene
> >
> > On 10/5/07, Wilt, Charles <WiltC@xxxxxxxxxx> wrote:
> > > Joe,
> > >
> > > Actually, I read the original post as "update" = CHAIN/UPDATE also,
> > > but the symptoms seemed to indicate that blocking might be
> > the issue;
> > > which would mean Gene was going READ/UPDATE.
> > >
> > > How about it Gene? Are you READing or CHAINing?
> > >
> > > Charles
> > >
> > > > -----Original Message-----
> > > > From: rpg400-l-bounces@xxxxxxxxxxxx
> > > > [mailto:rpg400-l-bounces@xxxxxxxxxxxx ] On Behalf Of Joe Pluta
> > > > Sent: Friday, October 05, 2007 11:54 AM
> > > > To: 'RPG programming on the AS400 / iSeries'
> > > > Subject: RE: SQL update vs RPG/DDS update
> > > >
> > > > > From: Wilt, Charles
> > > > >
> > > > > > I'm not sure what your problem is, Gene, but it is not that
> > > > > > dirty records are being hidden from users due to caching.
> > > > > > The beauty of the single level store is that there is no
> > > > such thing
> > > > > > as a dirty record.  When you access a record, you are
> > accessing
> > > > > > address of the virtual memory location where it
> > resides and that
> > > > > > memory is the same for all users.
> > > > >
> > > > > Not quite true Joe.
> > > > >
> > > > > Sounds like RPG may be blocking the i/o of the file.  In
> > > > which case,
> > > > > while the program has done the WRITE, the data is still in
> > > > the program
> > > > > buffers and has not yet been passed to the DB.
> > > >
> > > > I though I was pretty clear about updates vs. writes, Charles.
> > > > While writes may be blocked, the random nature of the
> > CHAIN/UPDATE
> > > > pretty much precludes any blocking.  I suppose you MIGHT see
> > > > blocking on an update primary file, but I haven't tried that in a
> > > > long time, and anyway that's not how I read the original
> > post.  Gene
> > > > specifically used the word "update" which I took to mean
> > updating a
> > > > record, which in turn means CHAIN/UPDATE.
> > > >
> > > > On the other hand I suppose it's possible that he was
> > talking about
> > > > locking the file and doing a bunch of writes.  In that
> > case, you're
> > > > absolutely correct that the writes could be blocked (which I also
> > > > said), and I would definitely go with the FEOD strategy;
> > that's what
> > > > I use as opposed to the FRCRATIO.
> > > >
> > > > Joe
> > > >
> > > > --
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