Integrity Constraint Checking in Federated Databases
نویسندگان
چکیده
A federated database is comprised of multiple interconnected databases that cooperate in an autonomous fashion. Global integrity constraints are very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. This paper presents a threefold contribution to integrity constraint checking in federated databases: (1) The problem of constraint checking in a federated database environment is clearly formulated. (2) A family of cooperative protocols for constraint checking is presented. (3) The di erences across protocols in the family are analyzed with respect to system requirements, properties guaranteed, and costs involved. Thus, we provide a suite of options with protocols for various environments with speci c system capabilities and integrity requirements.
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