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We revisit the standard chase procedure, studying its properties and applicability to classical database problems. We settle (in the negative) the open problem of decidability of termination of the standard chase, and we provide sufficient termination conditions which are strictly less over-conservative than the best previously known. We investigate the(More)
We formalize and study business process systems that are centered around "business artifacts", or simply "artifacts". Artifacts are used to represent (real or conceptual) key business entities, including both their data schema and lifecycles. The lifecycle of an artifact type specifies the possible sequencings of services that can be applied to an artifact(More)
We study data-driven Web applications provided by Web sites interacting with users or applications. The Web site can access an underlying database, as well as state information updated as the interaction progresses, and receives user input. The structure and contents of Web pages, as well as the actions to be taken, are determined dynamically by querying(More)
We state and solve the query reformulation problem for XML publishing in a general setting that allows mixed (XML and relational) storage for the proprietary data and exploits redundancies (materialized views, indexes and caches) to enhance performance. The correspondence between published and proprietary schemas is specified by views in both directions,(More)
Let &#931;<inf>1</inf>, &#931;<inf>2</inf> be two schemas, which may overlap, <i>C</i> be a set of constraints on the joint schema &#931;<inf>1</inf> &#8746; &#931;<inf>2</inf>, and <i>q</i><inf>1</inf> be a &#931;<inf>1</inf>-query. An <b>(equivalent) reformulation</b> of <i>q</i><inf>1</inf> in the presence of <i>C</i> is a &#931;<inf>2</inf>-query,(More)
We study the problem of rewriting queries using views in the presence of access patterns, integrity constraints, disjunction, and negation. We provide asymptotically optimal algorithms for finding minimal containing and maximal contained rewritings and for deciding whether an exact rewriting exists. We show that rewriting queries using views in this case(More)
Data-centric dynamic systems are systems where both the process controlling the dynamics and the manipulation of data are equally central. We study verification of (first-order) mu-calculus variants over <i>relational data-centric dynamic systems</i>, where data are maintained in a relational database, and the process is described in terms of atomic actions(More)