[Fwd: Re: Entity sets - containment and parent-child]

[Tim Tautges]

[Forgot to hit reply-all instead of reply...]

-------- Original Message --------
Subject: Re: Entity sets - containment and parent-child
Date: Thu, 12 Nov 2009 11:28:08 -0600
From: Tim Tautges <tautges at mcs.anl.gov>
To: Mark Beall <mbeall at simmetrix.com>
References: <7161BDA2-38F0-4C6D-86F2-68ED12D7A98D at simmetrix.com>	<4AFC37E7.7060502 at cae.wisc.edu> 
<A9D9B69E-292F-4CFB-8928-918E62A967F7 at simmetrix.com>

Having parent/child relations different from contains relations allows you to construct a graph with the sets (with sets
the nodes in the graph), while also storing sets in those nodes, all of this while also being able to distinguish these
things through the interface.  If the interface provided only contains relationships, applications could interpret them
for a given collection of sets as denoting parent/child relations, but they either wouldn't be able to store sets in the
nodes of the graph, or would need to further annotate them.  This would impose a limit on interoperability, as other
services or applications would need to know the details of that annotation before they could traverse the graph.

- tim

Mark Beall wrote:
> 
> So the only substantial difference between the containment and 
> parent-child relationship is that I can ask for the parents of an entity 
> set in a parent-child relationship whereas I can't in a containment 
> relationship (although the ability to do that would be easy enough to 
> add). In the containment relationship, the contained sets do play a part 
> in the entity set operations, but it would be trivial to ignore them in 
> the results.
> 
> Am I missing something here?
> 
> mark
> 
> 
> On Nov 12, 2009, at 11:29 AM, Jason Kraftcheck wrote:
> 
>> Mark Beall wrote:
>>> Entity sets can contain other entity sets, there can also be
>>> parent-child relations between entity sets. A couple questions on these
>>> concepts:
>>>
>>> 1) Does the parent-child relationship affect any of the operations on
>>> entity sets? For example, let's say I have a set A that has children B
>>> and C. If I get the entities in A is that just the entities in A or is
>>> it also the entities in B and C?
>>>
>>
>> The former.  The operation is applied only to the contents of the 
>> indicated set.
>>
> 
> 

-- 
================================================================
"You will keep in perfect peace him whose mind is
   steadfast, because he trusts in you."               Isaiah 26:3

              Tim Tautges            Argonne National Laboratory
          (tautges at mcs.anl.gov)      (telecommuting from UW-Madison)
          phone: (608) 263-8485      1500 Engineering Dr.
            fax: (608) 263-4499      Madison, WI 53706



-- 
================================================================
"You will keep in perfect peace him whose mind is
   steadfast, because he trusts in you."               Isaiah 26:3

              Tim Tautges            Argonne National Laboratory
          (tautges at mcs.anl.gov)      (telecommuting from UW-Madison)
          phone: (608) 263-8485      1500 Engineering Dr.
            fax: (608) 263-4499      Madison, WI 53706