performing search on information not contained to one document

[Saad Attieh via StackOverflow]

I was hoping someone could give some advice on the best way to do the following using the Google App Engine api:

Problem: Imagine a tree like structure where each root item (document to be searched) contains information common to all its children. Its children (other documents) have more specific information like their location. Is there a way I can perform a search that will match against a list of root documents but filter them to return a specific child that satisfies a constraint? Or, looking at it the other way, search across all children documents but having the search take into account information in its parent as if a local copy of it was in the child document?

Reason: I have a bunch of documents to be searched of which some share common information. I thought that I could save space by unifying all the common information into a document and link that document somehow to a series of others (the other documents should be treated as if they have a copy of the information but with more specific factors - location, date, etc).

Possible solutions:

Perhaps GAE gives the ability to perform a search on a set of documents previously returned on another search?

Find all child documents that match the condition working out a set of parents that they belong to, find all parent nodes that have information that match the search query and union across both sets?

Any advice would be appreciated

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