[INFOD-WG] Minutes - INFOD conference call, Thursday, June 28 2007

[Fisher, SM (Steve)]

Dieter,

I still don't think it is a problem. The integrity rules are there avoid
references to dead things. When C2 is created P will not be found. If C1
is evaluated after t3 then if it had an explicit reference to P then P
will be found otherwise not.

I will take a read through the use case document to try to make this
more concrete

Steve

> -----Original Message-----
> From: Dieter Gawlick [mailto:dieter.gawlick at oracle.com] 
> Sent: 29 June 2007 20:27
> To: Fisher, SM (Steve)
> Cc: INFOD
> Subject: Re: [INFOD-WG] Minutes - INFOD conference call, 
> Thursday, June 28 2007
> 
> Steve,
> 
> The flag is not enough to do the required check. 
> 
> Let us go through the following scenario:
> 
> 
> *	The is a property instance P created at t1
> *	There is a constraint C1 created at t2, P is in the 
> solution set of C1
> *	P is dropped with 'DISABLE NEW' at t3
> *	There is another constraint C2 created a t4, P is in 
> the solutions set of C2 - if the DISABLE NEW flag is discarded
> *	t1 < t2 < t3 < t4
> 	
> 
> The DISABLE NEW flag is obviously not enough to determine, 
> since P remains in the solution set of C1 but has to be 
> excluded from the solution set of C2. So, one has to keep 
> more information. There are certainly several obvious 
> possibility. Adding VALID-FROM and VALID-TO seems to be the 
> most sensible. 
> 
> I am not sure whether this is strictly an implementation 
> issue (just a recommendation) or whether we have to mandate 
> it. I think we need to mandate it and add it to the 
> specifications. Without additional information a GetMetaData 
> request would not be able to answer the following question: 
> What are the proper instances (and related entries) in the 
> solution set of C1 or C2?
> 
> Dieter
> 
> 
> Fisher, SM (Steve) wrote: 
> 
> 			*	The 'DISABLE NEW' support will 
> remain and is 
> 		considered to be useful. A possible 
> implementation is to add 
> 		a VALID-FROM and a VALID-TO field to (all?) 
> registry elements 
> 		and have a STILL-VALID and a TIME-OVERLAP check when 
> 		constraints are evaluated
> 		    
> 
> 	
> 	I don't understand this. It says in the spec "There is 
> an optional flag
> 	which can be set to "DISABLE NEW REFERENCES" which 
> results in the entry
> 	being dropped when the last reference to the entry has 
> been removed"
> 	
> 	The entry is fully visible to anybody currently using 
> it and remains
> 	valid forever and fully functional as long as somebody 
> has a reference
> 	to it.
> 	
> 	Steve
> 	  
> 
> 
> -- 
> 
> 
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