Research Issues in Structured and Semistructured Database Programming: 7th International Workshop on

The Seventh International Workshop on Database Programming Languages (DBPL99) took place in Kinloch Rannoch, Perthshire, UK from the 1st to the 3rd of September 1999. This series of workshops focuses on the interaction of theory and practice in the design and development of database programming languages. The workshop has occurred biennially since 1987, and was previously held in: Rosco?, Finist`ere, France (1987) Salishan, Oregon, USA (1989) Nafplion, Argolida, Greece (1991) Manhattan, New York, USA (1993) Gubbio, Umbria, Italy (1995) Estes Park, Colorado, USA (1997) The workshop, as always, was organised as a mixture of invited speakers, informal paper presentations and discussion. Attendance at the workshop was limited to those who submitted papers and members of the Programme C- mittee, to ensure a su?ciently small forum for useful discussion. Before ?nding their way into this volume, papers were refereed by at least three members of the Programme Committee. Sixteen of the 31 submitted papers were accepted for presentation at the workshop. In the tradition of the series, authors were - couraged to improve their papers based on both referees' comments and ensuing discussion at the workshop, and resubmit them for publication in this volume, after which a further stage of refereeing took place. The result, we believe, is a volume of high-quality and well-polished papers. Two invited presentations were given, by Luca Cardelli (Microsoft Research Labs, Cambridge, UK) and Alon Levy (University of Washington).