# Ann: DES 6.8 Released **URL:** \ **Category:** Announce\ **Tags:** software\ **Created:** [June 15, 2025, 9:46pm UTC](https://swi-prolog.discourse.group/t/ann-des-6-8-released/9057 "2025-06-15T21:46:38Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![fsaenzperez](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/fsaenzperez/32/50_2.png) [@fsaenzperez](https://swi-prolog.discourse.group/u/fsaenzperez)\ **Post date:** [June 15, 2025, 9:46pm UTC](https://swi-prolog.discourse.group/t/ann-des-6-8-released/9057/1 "2025-06-15T21:46:38Z")
[Apologies for multiple receptions] Hello. This is a mail just for informing that the new release Datalog Educational System version 6.8 [http://des.sourceforge.net](http://des.sourceforge.net) Mirrored at: [Datalog Educational System](https://www.fdi.ucm.es/profesor/fernan/des) And also its online interface has been made available at: [https://desweb.fdi.ucm.es](https://desweb.fdi.ucm.es) has been launched on June, 15th, 2025. This version includes several upgrades mainly following needs from teaching. First, the SQL semantic analyzer covers a wider set of errors, including those that are more common in the classroom. It detects inconsistency by resorting to functional dependencies, which can uncover typical errors in ORDER BY, GROUP BY and DISTINCT, among others. This is useful not only for this system but also for an automatic judge such as LearnSQL, which leverages this information for student feedback. TAPI commands have been extended for such a use case. Second, the Datalog debugger has been upgraded by reducing the number of questions posed to the user. Also, existing debugger commands have been extended, in particular for its TAPI interface with other systems such as DESweb and its graphical Datalog debugger. Third, an experimental implementation of the semi-naïve differential optimization has been performed in the DES engine, allowing for a better performance of linear recursive predicates. Fourth, the new version 0.19 of the desktop Java application ACIDE has been bundled with DES, including: colour themes, file encoding, stability and usability improvements. Finally, various enhancements and new commands have been added to DES, along with several refinements. A complete list of enhancements and fixed bugs is attached to the end of this message. Please, see [http://des.sourceforge.net](http://des.sourceforge.net) for details. Best regards. ============================================================= Fernando Saenz Perez Profesor Titular de Universidad / Associate Professor Home Page: [Fernando Sáenz Pérez Home Page Moved](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 6.8 of DES (released on June, 15th, 2025) - Enhancements: o Enhanced SQL semantic analysis with functional dependencies to uncover common pitfalls o Added the value loose for the command /sql\_semantic\_check, which includes more probabilities for false positives, though with more error detections o Avoided some rechecking in SQL semantic warnings o Experimental semi-naïve optimization for linear recursive predicates o Intermediate files from a Datalog debugging session are removed. Via TAPI, an ad-hoc command is used for this purpose o Enhanced full Datalog debugger by avoiding some subset questions derived from former user answers o Reduced set of automatic questions in the full Datalog debugger o Included dealing with an abort answer in the command /debug\_dl o Updated help for /debug\_dl o Wrong and missing data can be specified in the command /debug\_dl\_set\_node o New semantics for non-deterministic functions and impure deterministic functions (and counterpart function predicates) o Setting fuzzy mode disables non-Datalog languages. As well, setting a non-Datalog language in fuzzy mode selects (crisp-)Datalog o Commands /ls and /dir accepts a filename as argument. Also, extended help provided for these commands o New predicate and function substr with no length o Added support for the ALL and ANY quantifiers in the HAVING clause o Syntax of PostgreSQL simplified recursive views is supported (the same as already provided by DES but adding a RECURSIVE keyword) o SQL IS NULL operation extended to deal with expressions o The function cast can receive an expression as its first argument o Added exception to show internal errors when processing SQL queries o Uppercase ODBC connection names in commands do not need to be enclosed between single quotes (unless they contain a blank space) o ODBC connections become case-insensitive o Only one pass in the extensional table for fetching completed entries during fixpoint computation o Top-level goals which have been previously completed are not reprocessed (no fixpoint computation for them) o Completed top-N goals become cached in the extension table o Along user inputs, the extension table is only cleared for affected predicates o Function rand/1 is solved once for each call, avoiding resetting the seed along fixpoint computation o The command /fp\_info also displays statistics at each fixpoint iteration if they are enabled o When rules are removed (either manually or by the system when removing intermediate predicates), only entries in the extension table corresponding to those rules are removed, instead of clearing all the table o Host safety (sandboxing) extended to files out of the start path, which are not allowed to be accessed o New commands: - Changes: o The commands /drop\_all\_relations and /drop\_all\_tables apply the CASCADE option o The command /get\_relation renders null internal representation as null for non-TAPI invocations. Otherwise, it displays null internal representations o Predicates depending on non-deterministic functions (such as rand and current\_time) are not cached along user inputs o Non-deterministic functions (such as rand and current\_time) are evaluated only once for each solving path. This is relevant in two scenarios: providing different values for different depth calls along recursion, and different values for different choice points o Modified semantics of top-N queries: results are not affected by literal ordering - Fixed bugs: o The file des\_pchr.pl was not located where expected and the debugging session could not proceed o Some functions incorrectly propagated semantic bindings, leading to false positives for inconsistent conditions in SQL semantic checking o Some false positives in semantic warnings for EXCEPT, UNION, DIVISION and IN SQL operators o False positive in semantic warnings with COUNT DISTINCT when several relations were joined o False positive in semantic warnings for columns without aggregates in the HAVING conditions o False positive in semantic warnings for conditions over grouped columns occurring in the HAVING clause without an aggregate o Expressions in disjunctive bodies were not translated o Applying the full debugger to a Datalog predicate that is not the root in the PDG of a program did not find the erroneous predicate o Some relations enclosed between parentheses were not parsed o Some built-in predicate calls were not reordered to avoid instantiation exceptions. Some corner cases led to incomplete answers o Some uses of string casting yield to type errors o ODBC connections to Oracle failed o With ALTER TABLE it was possible to add existing column names o Type errors in expressions as arguments of built-in infix operators o The command /current\_flag failed when applied to a user flag o Dropping delimited tables in Oracle would fail o Datalog constant e (Euler number) raised an exception in comparison queries (bug introduced in version 6.7) o Selecting a string matching a built-in in SQL might fail o Open answers led exceptions o Non-ground goals in a top-n call might return incomplete answers for recursive predicates in the goal solving path o Incorrect pending choice point led /fp\_info on to display spurious text o The extension table was not cleared when disabling duplicates o Some statistics related to the extension table were not updated when inserting, deleting and updating in SQL statements o Under TAPI listings, an exception was raised for foreign keys with more than one attribute. //----------------------------// // ACIDE 0.19 Release Notes // // June, 15th 2025 // //----------------------------// - Enhancements, changes and fixed bugs: o Theme Management: Allows users to customize color schemes for the application’s interface, including font settings, and save configurations as themes. o File Encoding Selection: Enables users to choose the encoding format for loaded files. o Persistent Window Dimensions: ACIDE now retains its dimensions when restarted. o Configurable “Run” Button: Users can personalize the execution button behavior. o Resizable Number of Rules in Asserted Database: Improves visibility and management of rules within the database. o Enhanced Console Functionality: Users can now paste content directly at the cursor position within the console. o Project Closure Fix: Corrected ACIDE’s behavior when closing an active project. o Installer Creation: Developed an ACIDE installer for simplified setup. o Table Creation Using Datalog: Added support for defining tables through Datalog. o Line Wrapping Fix: Improved the text wrapping feature in the editor. o File Format Enhancements: Refined configuration and management of file formats. o Various Bug Fixes & Performance Optimizations: Implemented stability improvements and usability enhancements. IMPORTANT CAVEATS / KNOWN BUGS: o Ctrl+Mouse Wheel for resizing font display may take long time depending on the number of open file editors. o Opening medium-sized text files may take long time due to lexical analysis. No progress indicators are provided. Only when all editor windows are processed they are displayed. o As an alpha version, there are expected many bugs and incomplete functionalities. Please report them to fernan@sip.ucm.es