Re: Add fields to physical file without exclusive lock _ formerly Re: Stupid question of the century

[CRPence <CRPbottle@xxxxxxxxx>]

  A VIEW for inquiry only.  Also, using a VIEW to map /subfield/ 
data is limited for lack of a direct mapping function from a number 
of bytes to a chosen data type; i.e. only type to type mapping is 
allowed.  Mapping from physical data which is numeric BCD or integer 
into the VIEW is impractical and problematic, except as external UDF.

  The most appropriate solution IMO is to design the application to 
enable a switch to an alternate copy of the database [tables] being 
are referenced by that application.  As alluded in my earlier reply, 
there are likely to be other maintenance issues besides an ALTER of 
a TABLE which are going to require the application to be shut down, 
so solving only the one maintenance issue is limited in foresight.

Regards, Chuck

Charles Wilt wrote:
> However, those limitations could be eliminated simply by having
> a view defined with the subfields.
>
> On Mon, May 11, 2009 at 9:40 AM, Douglas Handy wrote:
> > I found it interesting that you no longer recommend this method
> > any more. Can you say why
> >
> > Alan Shore wrote:
> > > Two obvious things:  SQL and Query do not understand the
> > > subfields.