Re: Single level store & record blocking on update files (was RE:Where is IBM?)

[John Myers - MM <jmyersmm@xxxxxxxxxx>]

Dan,

Can I claim lunch from my earlier posting today?  I pointed out ...

CRTPF, CRTLF, CHGPF, or OVRDBF parameter FRCRATIO that controls blocking at 
the OS/400 level for writes and even updates.

or didn't you get that one ...

John


At 11:21 AM 4/24/2003, you wrote:
> Hi Doug,
>
> If you can prove to me that the AS/400 supports record blocking for update 
> files, even if limited
> to those files with no unique keyed APs, I will buy you lunch.  (How does 
> White Castle sound? <g>)
>
> Just to verify my sanity, I just wrote a simple CL/RPG:
> CL program:
>    Pgm
>      OVRDBF  RTATESTPF NBRRCDS(40) SEQONLY(*YES 40)
>      call    rtatestrpg
>      dltovr  RTATESTPF
>    Endpgm
>
> RPG program:
>      Frtatestpf uf   e             disk
>      C                   dou       *inLR
>      C                   read      rtatestpf                              LR
>      C                   if        not *inLR
>      C                   eval      rttxt = 'wassup?'
>      C                   update    rtatestr
>      C                   endif
>      C                   enddo
>
> No record blocking takes place.  The file is a physical with no key, and 
> with no logicals
> associated with it.  Upon the call to the RPG program, the job reports:
>   Open of member RTATESTPF was changed to SEQONLY(*NO)
>
> So, 'fess up.  How does one do this?
>
> - Dan
>
> --- Douglas Handy <dhandy1@xxxxxxxxxxxxx> wrote:
> > Dan,
> >
> > >On the AS/400, there is no record blocking for update files, 
> period.  I fail to see why this
> > is,
> > >especially in light of the AS/400's single level store.
> >
> > I think this is only true when there is a unique access path, and the
> > suppression of record blocking is simply to force an immediate test for
> > duplicate keys.
> >
> > Under SSP on the S/36, it could block them anyway and you didn't find 
> out about
> > the duplicates until the keysort when the file was closed.  (Remember those
> > nasty messages?)
> >
> > I believe the 400 can block record updates, provided the physical and 
> associated
> > logicals do not have a unique access path.  In practice this means most 
> files
> > cannot be blocked for update.
> >
> > Doug
>
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