Estimating the selectivity of queries is a crucial problem in database systems. Virtually all database systems rely on the use of selectivity estimates to choose amongst the many ...
Many applicationsstore data items for a pre-determined, finite length of time. Examples include slidingwindows over on-line data streams, where old data are dropped as the window...
In response to the widespread use of the XML format for document representation and message exchange, major database vendors support XML in terms of persistence, querying and inde...
Many information retrieval systems use the inverted file as indexing structure. The inverted file, however, is not suited to supporting incremental updates when new documents are ...
Recent interests on XML, Semantic Web, and Web ontology, among other topics, have sparked a renewed interest on graph-structured databases. A fundamental query on graphs is the re...