Obtaining Information about Queries behind Views and Dependencies

We consider the problems of finding and determiningcertain query answers and of determining containmentbetween queries; each problem is formulated in pres-ence of materialized views and dependencies under theclosed-world assumption. We show a tight relation-ship between the problems in this setting. Further,we introduce algorithms for solving each problem forthose inputs where all the queries and views are con-junctive, and the dependencies are embedded weaklyacyclic [13]. We also determine the complexity of eachproblem under the security-relevant complexity mea-sure introduced in [31]. The problems studied in thispaper are fundamental in ensuring correct specificationof database access-control policies, in particular in caseof fine-grained access control. Our approaches can alsobe applied in the areas of inference control, secure datapublishing, and database auditing.