In this paper, we first define a logical theory representing an XML database supporting XPath as query language and XUpdate as modification language. We then extend our theory with predicates allowing us to specify the security policy protecting the database. The security policy includes rules addressing the read and write privileges. We propose axioms to derive the database view each user is p...

SystemX is a natural language interface (NLI) to relational databases. The system has been used with a customer service statistical database, a research grants database, and an environmental database. Distinctive features of the NLI are its use of Head-Driven Phrase Structure Grammar (HPSG), treatment of complex noun phrases, integration of natural language with other input modes, use with a st...

We describe the extensions to the relational query language SQL that are necessary to support multilevel security in database management systems. In a multilevel secure database with data at a variety of sensitivity levels. The data classifications are provided by security assertions. Consequently, the data definition language and the data manipulat ion language should provide support for incor...

Information is playing an important role in our lives. One of the major sources of information is databases. Databases and database technology are having major impact on the growing use of computers. In order to retrieve information from a database, one needs to formulate a query in such way that the computer will understand and produce the desired output. The Structured Query Language (SQL) no...

We propose a language to define data update during schema versioning in a temporal object-oriented database. With this language, a user can express multi-schema modifications involving extensional data from different schema versions at the same time, improving the database environment with temporal and versioning features concerning database modification. We also provide the first steps towards...