[fitsbits] INHERIT and Hierarchical Grouping

[William Pence]

Doug Tody wrote (06-04-2007) regarding INHERIT:
> I agree with Steve that this is a simple example of a broader problem
> of associating relational entities.  FITS is in essence a relational
> system; every FITS object (even an image) is actually a table.
> INHERIT is a simple means for specifying the relationship between two
> or more tables composed as an MEF.  A FITS MEF is a simple container
> with one level of structure. ...
> The real problem with INHERIT is that it is a simplistic solution to
> what is a more general problem.  

Since no one else has commented on this yet, I'll just point out that 
the Hierarchical Grouping convention (now also open for public comment) 
  provides a more general mechanism for specifying the relationship 
between multiple HDUs that may be in different files or even on 
different computer systems.  Information about both the INHERIT and 
Hierarchical Grouping conventions is available at 
http://fits.gsfc.nasa.gov/fits_registry.html.

Does anyone have any comments about the Hierarchical Grouping convention 
itself?  Are there any deficiencies or limitations in this convention 
that have not been considered?  Are there alternative ways of 
accomplishing the same thing that might be simpler or offer more 
features than this convention?

Bill Pence
-- 
____________________________________________________________________
Dr. William Pence                       pence at milkyway.gsfc.nasa.gov
NASA/GSFC Code 662       HEASARC        +1-301-286-4599 (voice)
Greenbelt MD 20771                      +1-301-286-1684 (fax)