rql implementation

Dan was asking about whether any query language implements the stuff I've 
suggested in these messages:

UC&R 4.6 use case and discussion
http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JulSep/0491.html

getting more concrete about 4.6
http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JulSep/0403.html

The first message details Jena API bits, so it's implemented.

The second message details RQL features, so it's implemented.

The question arose about RQL's implementation details. Its web page says,

  The RQL Interpreter (v2.1) has been implemented in C++ on top of an ORDBMS
  (PostgreSQL v7.3 or higher) using a standard client-server architecture
  for Solaris and Linux platforms. It consists of four modules (a) the
  Parser, analyzing the syntax of queries; (b) the Graph Constructor,
  capturing the semantics of queries in terms of typing and
  interdependencies of involved expressions; (c) the SQL Translator, which
  rewrites RQL to efficient SQL queries; and (d) the Evaluation Engine,
  accessing the underlying database via SQL queries.

Which seems a fairly ordinary implementation strategy. It's not exotic in
any obvious sense.

Kendall Clark
-- 
You're one in a million
You've got to burn to shine