Re: Sorting records in Physical and Logical files

[vhamberg@xxxxxxxxxxx]

Pete

There is a physical order - the order things were put into the PF. That is usually where each new record is added at the end, unless you have said to re-use deleted records, where it's a 52-card pickup game.

Arrival sequence is just that, how the records arrived. You CAN put a key on a PF, although the advice on the 38 and 400 tended to be, don't put an index on the PF, just on logicals. But SQL typically has a different way of doing things - it really wants a primary key on a table (a PF), most especially, perhaps, for use with foreign key relationships. Those were not a part of the early form of the database on the 38.

HTH
Vern

-------------- Original message -------------- 
From: Pete Helgren <Pete@xxxxxxxxxx> 

> In the DDS? I though the point of a logical file was to build an index 
> that was an alternate to the default sorting sequence of the Physical 
> file (among other things). Yes, I could issue an ORDER BY using SQL or 
> OPNQRYF by I though the file had a "natural" sorting order that was set 
> by the DDS. 
>
> So, there is no way to define a physical file using DDS to sort records 
> in anything other than arrival sequence? 
>
> Pete 
>
> Alan Shore wrote: 
> > What you are seeing is in fact correct. You have to ORDER BY for the order 
> > you want 
> >
> >
> >
> > Alan Shore 
> > Programmer/Analyst, Direct Response 
> > E:AShore@xxxxxxxxxxx 
> > P:(631) 244-2000 ext. 5019 
> > C:(631) 880-8640 
> > "If you're going through Hell, keep going" - Winston Churchill 
> >
> > midrange-l-bounces@xxxxxxxxxxxx wrote on 08/21/2008 04:43:26 PM: 
> >
> >
> > > I thought I understood this but apparently I don't. 
> > >
> > > I have a physical and logical file with the following specs: 
> > >
> > > UNIQUE 
> > > R FASA809 TEXT('List Workfile') 
> > > ------------------------------------------------------- 
> > > record layout here: 
> > > SLWID 6S 0 COLHDG('Absence ID') 
> > > SLW# 6S 0 COLHDG('Seq. Number') 
> > > SLWSN 9S 0 COLHDG('Sub SSN') 
> > >
> > > K SLWID 
> > > K SLW# 
> > >
> > > The logical file looks like: 
> > >
> > > UNIQUE 
> > > R FASA809 PFILE(PASA809) 
> > >
> > > K SLWID 
> > > K SLWSN 
> > >
> > >
> > > The physical file has a randomly generated number in field SLW# and 
> > > since the keys are SLWID and then SLW# in that order. I would expect the 
> > > file to be ordered that way when I open it up in Query or a simple 
> > > select with no ordering in SQL. However, the file is always ordered in 
> > > arrival sequence. If I read through this file, I see the records in the 
> > > order in which they were written in the file. I *expected* them to be 
> > > ordered by the key sequence. 
> > >
> > > What did I miss or misunderstand? 
> > >
> > > Thanks 
> > >
> > > Pete