General scenario for problem
Suppose there is a data provider (source) with well-defined schema, API, etc… But it's read-only or cannot propagate pushed changes immediately or can filter changes. Well-known examples of such sources: wikipedia (dbpedia), freebase.
We need an approach to fill up data without losing synchronization with data source (we can not afford to just fork such data and maintain it).
More specific scenario
Data Source has facts :
[ [John, birthday, 1985], [John, died, 2013], [Vasya, birthday, 1970] ]
And we know, that actually John birthday is 1986 and he is alive at the moment. Also we know, that Vasya actually died last night and we need to provide users of our system with actual facts.
But we also need to sync up data with provider, for example, if data source will change Vasya's birthday to 1970 or edit information related to John death (for example, by adding triple [John, died, 2014]), we need to show this information, cause it's more actual.
My current situation
Currently I'm thinking about implementation of some 'complementary provider' and 'facade provider' around it and original data source. First will contain only data that differs from source provider data and the latter one will provide data read and manipulation mechanism to real application.
I tried to find existing solutions, but failed. But I suppose that it's a well known problem and I'm just do not know for what words to search.
So, how should I manage such problem in my application? And also, if you know some good sources about this problem (books, blog articles, researches and so on…), please provide references as well.