MathQL-1

A query language for RDF metadata

  • Features

Goals  and features

MathQL-1 is designed to achieve the following goals:
  1. Exploitation of RDF technology to manage metadata and compliance with the main requirements for an RDF query language. In particular:
  • MathQL-1 provides facilities for hierarchical constraints based on RDF Schema and for traversal of compound values of properties.
  • MathQL-1 provides a full set of Boolean operators to compose the query constraints and facilities for selecting URI's or literals by means of regular expressions.
  • MathQL-1 allows to customize the query results specifying what part of a solution should be preserved or discarded.
  • MathQL-1 has a well-conceived semantics defined in term of an abstract metadata model, imposes that queries return exhaustive solutions and includes a "select-from-where"-like construction.
  • MathQL-1 supports a machine-processable XML syntax as well as a human-readable textual syntax to achieve the best usability.
  1. Careful treatment of query results that are as important as the queries themselves. In particular:
  • MathQL-1 query results have a 4-dimensional geometry whereas other languages assume that query results are returned in 1-dimensional structures (i.e. lists of resources) or 2-dimensional structures (i.e. relational database tables). This allows to get better outcomes from queries returning structured results.
  • Besides the syntax for queries, MathQL-1 provides a syntax for query results with its own rigorously defined semantics.
  1. Exploitation of constructions borrowed from programming languages to allow sophisticated queries that need computation over the queried data. In particular:
  • MathQL-1 supports variables for storing intermediate query results, provides iterators over these results, has a conditional operator and includes logging facilities for debugging purposes.