Title: Querying Best Paths in Graph Databases,
Abstract: Querying graph databases has recently received much attention. We propose a
new approach to this problem, which balances competing goals of expressive
power, language clarity and computational complexity. A distinctive feature of
our approach is the ability to express properties of minimal (e.g. shortest)
and maximal (e.g. most valuable) paths satisfying given criteria. To express
complex properties in a modular way, we introduce labelling-generating
ontologies. The resulting formalism is computationally attractive -- queries
can be answered in non-deterministic logarithmic space in the size of the
database.