Multidatabase Transaction and Query Processing in Logic

          Eva Kühn and Franz Puntigam and Ahmed K. Elmagarmid
    University of Technology Vienna, Institute of Computer Languages
           Argentinierstr. 8, A-1040 Vienna, Austria, Europe
                 {eva,franz}@mips.complang.tuwien.ac.at

The integration of multiple autonomous and heterogeneous database systems
into one multidatabase system requires a powerful language which serves
both for specifying queries and transactions. In our previous work we
proposed a Prolog-based language for specifying queries in multidatabase
systems. In this paper, we have introduced a parallel Prolog-based query
language which serves well as a concurrent specification language for the
representation of a recently proposed transaction model called
``Flex Transactions''. We have described the extended language by using
examples and have shown its advantages in comparison to existing parallel
logic languages. A prototype implementation of this language (VPL, Vienna
Parallel Logic Language) has been developed at the University of Technology
Vienna and is currently under investigation in the Interbase Project at
Purdue University.