Query Language for Prometheus

: This document presents the query language developed for the Prometheus database [RKB99]. This language is based on graphs and provides the user with a means to define the data to be extracted from the database and its manipulation. The language requires the definition of patterns that can be matched against the set of data available in the database and return instances. 1. Introduction We have defined in [RKB99] a database model based on graphs and that puts the emphasis on relationships. This model was designed to support the Prometheus taxonomic model [PK99] and provide taxonomists with means of manipulating taxonomic data naturally and effectively. Since taxonomists are not computing specialists, the choice of graphs also has the advantage of being naturally represented graphically and easily coupled with a graphical programming language (e.g. [PL94], [RK97]). First we define briefly the Prometheus model in section 2, then we explain the operations necessary on graphs in section ..