[Apologies for multiple receptions] Hello. This is a mail just for informing that the new release
Datalog Educational System version 1.6.2 http://des.sourceforge.net has been launched on March, 10th, 2009 and ported to GNU Prolog 1.3.1 Release notes are attached to the end of this message. Please, see http://des.sourceforge.net for details. Best regards. ============================================================== Fernando Sáenz Pérez Profesor Titular de Universidad / Associate Professor Home Page: http://www.fdi.ucm.es/profesor/fernan Tel: + 34 913947642. Fax: + 34 913947547 Despacho / Office: 435 (4ª planta / 4th floor) Dept. Ingeniería del Software e Inteligencia Artificial / Department of Software Engineering and Artificial Intelligence Universidad Complutense de Madrid Facultad de Informática C/Profesor José García Santesmases, s/n E - 28040 Madrid. Spain ============================================================== Version 1.6.2 of DES adds to previous version (1.6.1): Enhancements: o Null values has been included both for Datalog programs and SQL statements o Novel outer join Datalog functions: lj/3, rj/3, and fj/3 o Outer join SQL clauses added: LEFT [OUTER] JOIN, RIGHT [OUTER] JOIN, and FULL [OUTER] JOIN o Solving algorithm enhanced for stratified queries. Partial recomputations of lower-stratum predicates are avoided o Compilation of SQL WHERE conditions to Datalog rules now provides shorter and more efficient programs o Disjunctions in Datalog rule bodies o New commands: - /development Switch Enables/Disables development listings. These listings show the source-to-source translations needed to handle null values, Datalog outer join built-ins, and disjunctive literals - /development Displays whether development listings are enabled - /simplification Switch Enables/Disables simplification of Datalog rules. Rules with equalities, true, and not(BooleanValue) are simplified - /simplification Displays whether rule simplification is enabled o WHERE conditions accept arithmetic expressions (e.g., 1+t.a>3) o Display of the number of undefined computed tuples, and the number of tuples in the extension table answer and call sets o Parentheses in Datalog rule bodies, not only in arithmetic expressions, are allowed o Parentheresed listings of Datalog rule bodies, making more readable bodies with conjunctions and disjunctions o Simplification of rules containing equalities Changes: o Rule listings are grouped by predicate name and arity. For a given predicate name and arity, facts come first, followed by rules with right hand sides. The order of facts and rules follows Prolog standard order between terms o Datalog rules resulting from translating views change the naming convention to (the more readable) ViewName_Arity_Number in lieu of ViewName$pNumber o Results from Datalog autoviews are given the relation name answer instead of autoview o Pretty-print is applied to all Datalog rule listings o Safety warnings are not hidden by computability warnings Fixed bugs: o Unformatted SQL statement display for certain conditions and joins o Parsing error for EXISTS clause (no blanks between EXISTS and opening parenthesis were allowed) o SQL arithmetic functions could only be written in lowercase o Some WHERE conditions incorrectly translated into Datalog conditions (bug introduced in version 1.6.1) o Some WHERE conditions involving parentheses incorrectly parsed o Correlated SQL queries with non-basic conditions were incorrectly translated into Datalog rules o DELETE SQL statements failed to be parsed (copy-paste bug introduced in version 1.6.1) o Some unsafe Datalog queries were not rejected for computation (as X=Y) o During startup batch processing of des.ini, some tasks upon exceptions were not performed o Typing des. in a Prolog interpreter after abnormally quitting the system did not result in exception catching anymore o A class of unsafe rules was not be able to be preprocessed for reordering body goals, yielding non-termination o Incomplete error message Known bugs: o The projection list of a natural outer join is not correct in all cases Caveat: o Computable SQL statements follow the grammar in the manual. The current grammar parses extra clauses which cannot be computed yet (e.g., GROUP BY, ORDER BY, ...) _______________________________________________ Users-prolog mailing list [email protected] http://lists.gnu.org/mailman/listinfo/users-prolog
