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		| Paper: | 
		The SkyView Data Model: Handling Heterogeneous Data Using Dynamic Software | 
	 
	
		| Volume: | 
		521, Astronomical Data Analysis Software and Systems XXVI | 
	 
	
		| Page: | 
		462 | 
	 
	
		| Authors: | 
		McGlynn, T.; McDonald, L. | 
	 
	
	
		| Abstract: | 
		The SkyView Virtual Telescope allows users to query over 75 distinct datasets
 of astronomical imagery including more than 190 distinct surveys.  
 These holdings
 are extraordinarily diverse ranging over more than 15 orders of magnitude 
 in frequency and 5 orders of magnitude in resolution.
 To accommodate supporting these data, SkyView has developed
 a simple data model for surveys. 
 Nor surprisingly, given the diverse origins of the datasets included, some
 surveys do not easily fit within this model.  
 The conventional approach to dealing with such outliers is to 
 build a layer on top of the actual data which more faithfully adheres
 to the data model.  
 With SkyView we have used a somewhat alternative approach.
 We allow the data model to define new behaviors in the SkyView code itself
 either by customizing the use of existing capabilities or pointing to new
 classes that have non-standard behavior. 
 This approach is feasible since in modern computer languages the code that is
 run can be selected dynamically with new classes completely overriding traditional
 behavior.
 This paper describes this approach and considers how it may become
 more useful as our software structures become increasingly dynamically linked. | 
	 
	
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