Datalog Educational System Files

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  | DES INSTALLATION (quick guide) |
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Windows Binary Distribution with ACIDE GUI
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- Double-click on des_acide.jar for starting the 
  ACIDE GUI. Requires Java JRE 1.8

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Windows Binary Distribution
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- Double-click on deswin.exe for starting the Windows
  application
- Execute des.exe for starting the console application

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Linux/MacOSX Binary Distribution with ACIDE GUI
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- Add execute permission to files des and des_start,
  typically with:
    chmod +x ./bin/des
    chmod +x ./bin/des_start
  or from the file explorer.
- Check unixodbc is installed
- Start ACIDE from a terminal with:
  java -jar des_acide.jar  
  Requires Java JRE 1.8

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Linux/MacOSX Binary Distribution
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- Add execute permission to files des and des_start,
  typically with:
    chmod +x ./bin/des
    chmod +x ./bin/des_start
  or from the file explorer.
- Check unixodbc is installed
- Start ./des in a terminal from its installation path

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Windows Source Distributions
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1. Create a shortcut in the desktop for running the Prolog 
   interpreter of your choice. 
2. Modify the start directory in the "Properties" dialog box 
   of the shortcut to the installation directory for DES. 
   This allows the system to consult the needed files at startup.
3. Append the following options to the Prolog executable complete 
   filename, depending on the Prolog interpreter you use:
   (a) SICStus Prolog: -l des.pl
   (b) SWI Prolog: -g "ensure_loaded(des)" (remove --win_app if 
     present)
Another alternative is to write a batch file similar to the 
script file described just in the above section.
    
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Linux/MacOSX Source Distributions
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You can write a script for starting DES according to the 
selected Prolog interpreter, as follows:
(a) SICStus Prolog: 
    $SICSTUS -l des.pl 
    Provided that $SICSTUS is the variable which holds 
    the absolute filename of the SICStus Prolog executable.
(b) SWI Prolog: 
    $SWI -g "ensure_loaded(des)"
    Provided that $SWI is the variable which holds the 
    absolute filename of the SWI Prolog executable.

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More Information: 
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- See User Manual
  'Documentation' entry in 
  http://des.sourceforge.net/html/download.html
- http://des.sourceforge.net


Version Devel of DES (released on November, 20th, 2020)
 
* Enhancements:
  o Improved automatic type casting for dealing with values of 
    different data types, both at compile-time and at run-time 
  o More deterministic type inference, improving analysis time
  o Improved SQL semantic analysis precision for some built-in 
    predicates
  o Better compilations for some aggregate metapredicates, reducing 
    the number of arguments
  o Better SQL compilations by simplifying evaluable goals
  o Better compilations for relations in group_by predicate 
    (intermediate predicates with less arguments)
  o Some bad uses of aggregates are issued at compile-time (as 
    errors), instead of at run-time (as an exception)
  o SQL grouping error messages extended with column names
  o Left operand of SQL LIKE operator can be a tuple of expressions 
    (instead of just constants or columns)
  o SQL strings can include escaped apostrophes with the backslash, in
    addition to the already supported double apostrophe
  o The SQL ALTER TABLE statement has been extended to deal with table
    columns: redefining a column (both its data type and constraints) or
    only changing its data type
  o ORDER BY expressions can contain aggregates and include positional
    notation
  o Added SQL logical operator XOR
  o Added round function with two arguments, and its corresponding 
    predicate 
  o Time and datetime formatting (in addition to the already supported
    date formatting). Enabled by default and set with the command 
    /format_datetime
  o The command /date_format admits date formats delimited by single 
    quotes
  o New commands:
    - /describe Relation Synonym for /db_schema Relation, where 
      Relation can only be either a table or a view, possibly qualified 
      with the database name (as connection:relation)
    - /tapi_log Display whether TAPI logging is enabled. If enabled, 
      both TAPI commands and their results are not logged
    - /tapi_log Switch Enable or disable TAPI logging (on or off, 
      resp.) If enabled, both TAPI commands and their results are not 
      logged
    
* Changes:
  o Changing the type casting mode recompiles views in the local 
    database
  o TAPI inputs and their results are not logged by default
  o Most types from external databases are shown normalized, instead 
    using their particular naming
  o Normalized name types for ODBC connections


* Fixed bugs:
  o A case in simplifying goals was incorrect, dealing to incorrect 
    translations and semantic deductions
  o The CASCADE modifier parsing was included in version 6.4 but its 
    processing was not implemented
  o Wrong partial reduction when unfolding some metapredicates for 
    disjunctions
  o A non-valid date format specified by the command /date_format 
    would lead to non-termination
  o Incorrect type error when comparing a string constant with a 
    limited-size string type
  o Incorrect exception in SQL truncate function
  o ODBC varchar type sizes were not correctly retrieved
  o In SICStus distros, nulls were not grounded for external 
    connections
  o Some SQL error messages about bad groupings were not correct
  o Logging information was duplicated in /status