document: Efficiently evaluating graph constraints in content-based publish\/subscribe We introduce the problem of evaluating graph constraints in content-based publish\/subscribe ( pub\/sub ) systems . This problem formulation extends traditional content-based pub\/sub systems in the following manner : publishers and subscribers are connected via a ( logical ) directed graph G with node and edge constraints , which limits the set of valid paths between them . Such graph constraints can be used to model a Web advertising exchange ( where there may be restrictions on how advertising networks can connect advertisers and publishers ) and content delivery problems in social networks ( where there may be restrictions on how information can be shared via the social graph ) . In this context , we develop efficient algorithms for evaluating graph constraints over arbitrary directed graphs G. We also present experimental results that demonstrate the effectiveness and scalability of the proposed algorithms using a realistic dataset from Yahoo ! 's Web advertising exchange .
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