RE: CREATE INDEX and name only some columns

["Wilt, Charles" <WiltC@xxxxxxxxxx>]

Same reason you'd build views or SELECT statements that specify individual fields and not *.

1) Better performance
2) You can change the DB without needing to recompile all the program.

Granted point 2 isn't as important now-a-days given CM software.  Unless your shop requires testing of
any programs moving into production even if it was just a recompile.

Charles


> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx 
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of 
> Tommy.Holden@xxxxxxxxxxxxxxxxxxxxx
> Sent: Tuesday, September 11, 2007 5:28 PM
> To: Midrange Systems Technical Discussion
> Subject: RE: CREATE INDEX and name only some columns
>
> my same statement regarding select/omit LFs still applies.  
> why build LFs that have only specific fields???  What exactly 
> do you gain from that? not much.  except more LFs with the 
> same key structure containing other selected fields (or 
> heaven forbid includes all PF fields)??
>
> Thanks,
> Tommy Holden
>
>
>
> vhamberg@xxxxxxxxxxx
> Sent by: midrange-l-bounces@xxxxxxxxxxxx
> 09/11/2007 04:23 PM
> Please respond to
> Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
>
>
> To
> Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
> cc
>
> Subject
> RE: CREATE INDEX and name only some columns
>
>
>
>
>
>
> Tommy - Jeff is not using either select/omit or join 
> logicals, as far as I 
> can see. He just wants the ability to have fewer than all the columns 
> along with the index, which is only available with 
> DDS-defined logicals, 
> not DDL-defined logicals - heh - otherwise known as indexes and views.
>
> It is true that views and indexes can be used in F-specs - but not 
> combined.
>
> So he can create the PF with DDL, as others have suggested - 
> then make the 
> LF over it to get the column-filtering he wants, and keyed.
>
> Vern
>
>  -------------- Original message ----------------------
> From: Tommy.Holden@xxxxxxxxxxxxxxxxxxxxx
> > "As long as you're using native I/O you're _are_ going to 
> have to have 
> DDS 
> > logicals.  Unless you're
> > writing/rewriting from the ground up to avoid the need for 
> capabilities 
> > only available to DDS
> > logicals."
> >
> > i have to disagree on this point.  DDS logicals are not 
> necessary for 
> > native I/O.  as to avoiding the need for DDS capabilites 
> you don't have 
> to 
> > rewrite the world.  I've never been a fan of select/omit or 
> join logical 
>
> > files.  it becomes a tedious pain when you have 15 LFs that 
> are keyed in 
>
> > the order you need but every fricking one has a select/omit 
> which makes 
> > them totally useless to you.  this is one of the reason 
> you'll see 5 
> > billion LFs over a single PF.  create the LF (or SQL index) 
> and code for 
>
> > your conditions...
> >
> > Thanks,
> > Tommy Holden
> >
> >
> >
> > "Wilt, Charles" <WiltC@xxxxxxxxxx> 
> > Sent by: midrange-l-bounces@xxxxxxxxxxxx
> > 09/11/2007 03:48 PM
> > Please respond to
> > Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
> >
> >
> > To
> > "Midrange Systems Technical Discussion" <midrange-l@xxxxxxxxxxxx>
> > cc
> >
> > Subject
> > RE: CREATE INDEX and name only some columns
> >
> >
> >
> >
> >
> >
> > Why?
> >
> > If you need it for native I/O, use a DDS logical.
> >
> > As long as the physical file is defined with DDL, you get 
> the important 
> > benefits of using DDL vs. DDS
> > including:
> > -Validation on Write instead of Read
> > -64K Access paths (when logical shares an SQL access path)
> >
> > As long as you're using native I/O you're _are_ going to 
> have to have 
> DDS 
> > logicals.  Unless you're
> > writing/rewriting from the ground up to avoid the need for 
> capabilities 
> > only available to DDS
> > logicals.
> >
> > HTH,
> > Charles
> >
> >
> > > -----Original Message-----
> > > From: midrange-l-bounces@xxxxxxxxxxxx 
> > > [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Jeff Crosby
> > > Sent: Tuesday, September 11, 2007 4:29 PM
> > > To: 'Midrange Systems Technical Discussion'
> > > Subject: RE: CREATE INDEX and name only some columns
> > >
> > > Poop.
> > >
> > > Yes I need it for native I/O.  I'll figure out another way. 
> > > But I _AM_ going to define this file via DDL.
> > >
> > > --
> > > Jeff Crosby
> > > UniPro FoodService/Dilgard
> > > P.O. Box 13369
> > > Ft. Wayne, IN 46868-3369
> > > 260-422-7531
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