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We introduce an auditing framework for determining whether a database system is adhering to its data disclosure policies. Users formulate audit expressions to specify the (sensitive) data subject to disclosure review. An audit component accepts audit expressions and returns all queries (deemed " suspicious ") that accessed the specified data during their(More)
Contextual preferences take the form that item i1 is preferred to item <i>i</i><sub>2</sub> in the context of <i>X</i>. For example, a preference might state the choice for Nicole Kidman over Penelope Cruz in drama movies, whereas another preference might choose Penelope Cruz over Nicole Kidman in the context of Spanish dramas. Various sources provide(More)
The EPCglobal consortium defines standards to enable data sharing of electronic product code related information within and between enterprises, which typically comprises events of RFID readers as well as product information about the tagged products. An EPC-global network consists of nodes, each of which may have complex data usage and sharing policies and(More)
SQL-based data mining algorithms are rarely used in practice today. Most performance experiments have shown that SQL-based approaches are inferior to main-memory algorithms. Nevertheless, database vendors try to integrate analysis functionalities to some extent into their query execution and optimization components in order to narrow the gap between data(More)
RFID event data repositories such as EPCglobal's EPC information services (EPCIS) contain valuable information that is not only useful for ad-hoc data analysis but also for on- demand information needs according to the publish-subscribe paradigm. The EPCIS standard defines a query control interface that allows running queries against events and master data(More)
  • Ralf Rantzau
  • 2004
Algorithms for finding frequent itemsets fall into two broad classes: (1) algorithms that are based on non-trivial SQL statements to query and update a database, and (2) algorithms that employ sophisticated in-memory data structures , where the data is stored into and retrieved from flat files. Most performance experiments have shown that SQL-based(More)
Today many applications routinely generate large quantities of data. The data often takes the form of (time) series, or more generally streams, i.e. an ordered sequence of records. Analysis of this data requires stream processing techniques which differ in significant ways from what current database analysis and query techniques have been optimized for. In(More)