DES 3.0 Released

[fernan]

[Apologies for multiple receptions]

Hello.
This is a mail just for informing that the new release 

  Datalog Educational System version 3.0 
  http://des.sourceforge.net

has been launched on May, 10th, 2012, and ported to

  GNU Prolog 1.4.0

There are two relevant enhancements in the current release: 
Predicate persistency supported by external databases, and 
an extended SQL debugger. The first one motivates raising 
the major version as it opens a brand new scenario for 
several reasons: First, predicates are no longer limited by 
available memory; instead, persisted predicates are using as
much secondary storage as needed and provided by the 
underlying external database. Second, processing is directed
to the external database for those rules that can be 
projected, and to the deductive engine for rules that can 
not. This way, one can take advantage of the external 
database performance and scalability. Third, queries which 
are not possible in an external database can be solved by 
the deductive engine. So, one can extend external database 
expressiveness with the added features in DES. Finally, as 
several ODBC connections are allowed at a time, different 
predicates can be made persistent in different DMBSs, which 
allows for interoperability among external relational 
engines and the local deductive engine, therefore enabling 
business intelligence applications. With respect to the new 
SQL Debugger version, which is a new implementation, it also
now accept user information about wrong and missing tuples, 
allowing to focus the questions directed to the user on more
precise error sources, therefore preventing many questions 
involving large sets of data. New ports to SICStus Prolog 
4.2.1 and SWI-Prolog 6.0.2 have been provided. Finally, the 
license has been relaxed to LGPL version 3.

A complete list of enhancements, changes and fixed bugs is 
attached to the end of this message. 
Please, see http://des.sourceforge.net for details.

  Best regards.



=============================================================
Fernando Saenz Perez
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. Ingenieria del Software e Inteligencia Artificial / 
Department of Software Engineering and Artificial 
Intelligence
Universidad Complutense de Madrid
Facultad de Informatica
C/Profesor Jose Garcia Santesmases, s/n
E - 28040 Madrid. Spain

=============================================================



Version 3.0 of DES (released on May, 10th, 2012)

* Enhancements:
  o New commands:
    + /close_db Name Close the given ODBC connection. TAPI 
      enabled
    + /drop_assertion Drop an assertion
    + /start_stopwatch Start stopwatch. Precision depends on
      host Prolog system (1 second or milliseconds)
    + /stop_stopwatch Stop stopwatch
    + /reset_stopwatch Reset stopwatch
    + /display_stopwatch Display stopwatch
    + /list_persisted Display the persisted predicates. TAPI
      enabled
    + /show_dbs Display the open database connections. TAPI 
      enabled
    + /show_sql Display whether SQL statements which are 
      sent to an external database are to be displayed
    + /show_sql Switch Enable or disable display of SQL 
      statements which are sent to an external database (on or
      off, resp.)
    + /use_db Name Make Name the current ODBC connection. 
      TAPI enabled
    + /dbschema Connection:Name Display the database schema 
      for the given view or table name in the given connection
    + /license Display GPL and LGPL licenses. If not found, 
      please visit http://www.gnu.org/licenses
  o New assertions:
    + :-persistent(PredSpec[,Connection]))  Make a  
      predicate to persist on an external RDBMS via an ODBC 
      connection. PredSpec can be either the pattern 
      PredName/Arity or PredName(Schema), where Schema can be 
      either ArgName1, …, ArgNameN or ArgName1:Type1, …, 
      ArgNameN:TypeN. If a connection name is not provided, 
      the current open database is used
  o Binary flags in commands are no longer case-sensitive
  o New port to SICStus Prolog 4.2.1. This release fixes in 
    particular some issues with ODBC connections (exceptions 
    about misencoded string in non-ASCII ODBC messages, and 
    incorrect handling of SQL_BIGINT and related types)
  o New port to SWI-Prolog 6.0.2
* Changes:
  o License has been relaxed to GNU Lesser General Public 
    License
  o New versions of command /debug_sql does not admit a 
    traversing order yet (order option removed)
  o Release notes of older DES versions are moved to the new
    document: releasenotesDES.pdf
* Fixed bugs:
  o Some spanned inputs without leading blanks in multi-line
    mode were not recognised
  o Duplicated object rules were retrieved several times
  o Some commands were not recognized in mixed or uppercase
  o Some listings in development mode did not display all 
    rules
  o Some hypothetical queries led to exceptions
  o Existency of table and attributes in an INSERT SQL 
    statement with a SQL data source was not checked
  o Parsing of a SQL relation separated by a leading space 
    before the comma lead to syntax error
  o Predefined strong constraints relating a tuple of column
    names were rejected if its lexicographic order did not 
    match the order in which they occur in table definition
  o Running info were logged
  o Some rules with conjunctions and disjunctions were not 
    parsed correctly from consulted files
  o GNU Prolog source distribution stopped processing of 
    batch files while encountering a /shell command
  o Predicate dependency graph and strata were not computed 
    after issuing DML SQL statements INSERT, DELETE and DQL 
    SQL statement WITH