RE: Externalize DB/IO

Hi Jim, et.al. -

>If you are adding new fields there are a few ways to go about it,
>mostly dependent on the programming language you are using.  The
>easiest way is to just not pass back these new fields for the old
>call.  Create a new call that passes back the full records and have
>any program that needs these fields call the new procedure.  That 
>way you have to modify only the programs that need it.

If you remember from the lengthy discussion on the OpenERP list, one of the
possibilities is to use a service program for the I/O and have the service
program own the storage for the record, rather than the caller.  That way so
long as you add fields to the end of the storage, and just pass a pointer to
the storage area back to the caller, you don't have to even know what
version of the record that the caller knows about.  And of course the
storage area mapping does not have match the actual file layout.  The data
doesn't all have to even be in one file.

Ken
Southern Wine and Spirits of Nevada, Inc.
Opinions expressed are my own and do not necessarily represent the views of
my employer or anyone in their right mind.

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