Abstract: In order to achieve efficient execution plans for queries comprising userdefined data types and predicates, the database system has to be provided with appropriate index ...
We study the problem of maintaining recursively-de ned views, such as the transitive closure of a relation, in traditional relational languages that do not have recursion mechanis...
This paper presents a system for querying treebanks. The system consists of a powerful query language with natural support for cross-layer queries, a client interface with a graph...
There exist many interrelated information sources on the Internet that can be categorized into structured (database) and semistructured (documents). A key challenge is to integrat...
XML is here as the internet standard for information exchange among e-businesses and applications. With its dramatic adoption and its ability to model structured, unstructured and...