Re: Select * into an external DS, and then adding columns

[Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx>]

Valid point, Glenn - it wasn't clear to me that this is what Deiter was 
saying.

And since a view presumably has the column list one wants for a certain 
purpose, the select * is fine there.

So perhaps I can revise my statement to say to almost always use PFs in 
the SELECT within a view?

Thanks
Vern

On 2/6/2016 3:57 PM, Glenn Gundermann wrote:
> Vern,
> The idea is to use a view and not the physical. If the physical is altered, the view isn't broken.
> Many people believe this is the best way to go.
> Yours truly,
> Glenn Gundermannglenn.gundermann@xxxxxxxxx (416) 317-3144-------- Original message --------From: Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx> Date: 2016-02-06  4:24 PM  (GMT-05:00) To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx> Subject: Re: Select * into an external DS, and then adding columns
> I am not sure of Dieter's context here - but the recommendation never to
> use a PF in a select statement goes completely against IBM's strong
> recommendation to almost always do that - the optimizer will always go
> back to the PF, anyhow, then find candidate indexes with which to run
> the query. So specifying a PF cuts out some processing time.
>
> Now there can be exceptions - one is using select/omit logicals that
> match the selectivity in a WHERE clause. Things may have changed around
> that landscape with the ability to create sparse indexes now, which are
> like S/O LFs in a way.
>
> Cheers
> Vern
>
> On 2/6/2016 1:07 PM, D*B wrote:
> > .... as long as the SQLDA to receive the values is compatible with the
> > SQLDA of the ResultSet the values are assigned in the order, they are
> > coming. The (external) DS is resolved to the Format at compiletime,
> > the * from select (*) is expanded at runtime. One recommendation of
> > mine is: don't use a PF in a select statement (never ever), don't
> > change a View (never ever) and you will be happy with select * in all
> > scenarios.
> >
> > D*B
> >
> > <Charles>
> > That's an interesting point...
> >
> > Since Alter Table does add columns to the end of the table...
> >
> > Wonder what would happen if you recreated the table with the new
> > columns in
> > the middle.
> >
> > Charles
> > </Charles>