Graphical Web Based Tool for Generating Query from Star Schema

Novice users have difficulty to generate structured query language from the star schemas because they are not familiar with formulating SQL queries and SQL syntax. This study proposed graphical web based tool to generate queries from star schema and represent the data in tabular or graphical forms which help novice user to formulate SQL query. A prototype for a web based tool to generate the query has been developed using Java Server Pages programming language. The developed tool can facilitate complex query construction which is faced by non-technical and/or novice users. The output of SQL query is presented in tabular and graphical forms which can help users especially top management in better understanding and interpreting query results

Efficient Database Risk Management Using BSP and Fuzzy Logic

Increasing passion for internet throughout the world causes the exponential growth in the web applications and distributed techniques. Due to high usage of web applications massive transactions are happening at the database server side. Even though databases are well equipped with powerful tools, most of the times they are unable to fulfill the user’s demand and resulting in longer waiting queues or crashing of databases. So many methods and systems are existing to handle the overflowing database queries, but most of them again take longer time to get rid of the situation. This paper put forwards an idea of handling this risk situation of the database by collecting all the queries in a Queue and thereby evaluating risk aware situation by fuzzy classification. Once the risk awareness is notified then these queries in the queue are committing quickly using batch stream processing technique to avoid longer waiting queues of the queries for execution. DOI: 10.17762/ijritcc2321-8169.15079

Contributions aux notions d’équivalence relationnelle dans un contexte d’essais

Plusieurs systèmes d’aide à l’enseignement ont la capacité d’évaluer et de comparer les travaux des étudiants. Dans un contexte d’enseignement des systèmes de gestion de bases de données relationnelles, une telle comparaison nécessite l’étude des équivalences entre les requêtes et leurs résultats. Plus précisément, les équivalences de requêtes peuvent être vérifiées selon deux modèles, à savoir le modèle SQL et le modèle relationnel. Bien que plusieurs travaux de recherche aient déjà été menés pour la comparaison de requêtes et de résultats basés sur des équivalences syntaxiques et sémantiques, la plupart d’entre eux ne traitent pas les deux modèles. Dans ce mémoire, nous proposons quatre algorithmes: les deux premiers pour la vérification de l’équivalence sémantique (selon le modèle SQL et selon le modèle relationnel) et les deux autres algorithmes pour la vérification de l’équivalence des résultats (selon le modèle SQL et selon le modèle relationnel). Les deux premiers reposent principalement sur un algorithme proposé par Cohen. L’algorithme appliqué au modèle SQL prend en compte les nuls ainsi que sept paramètres, à savoir le nom des attributs, le nombre d’attributs, le nombre de lignes, le type des attributs, la valeur des attributs, l’ordre des attributs et l’ordre des lignes. L’algorithme appliqué au modèle relationnel prend en compte cinq paramètres, à savoir le nom des attributs, le nombre d’attributs, le nombre de lignes, le type des attributs et la valeur des attributs. Ces algorithmes s’appliquent pour un sous-ensemble important des requêtes SELECT (comprenant notamment les clauses GROUP BY et HAVING). Ils ont été mis en œuvre dans l’outil Themis que nous avons développé. Themis permet en outre de vérifier partiellement la syntaxe des requêtes

A Syntactical Reverse Engineering Approach to Fourth Generation Programming Languages Using Formal Methods

Fourth-generation programming languages (4GLs) feature rapid development with minimum configuration required by developers. However, 4GLs can suffer from limitations such as high maintenance cost and legacy software practices. Reverse engineering an existing large legacy 4GL system into a currently maintainable programming language can be a cheaper and more effective solution than rewriting from scratch. Tools do not exist so far, for reverse engineering proprietary XML-like and model-driven 4GLs where the full language specification is not in the public domain. This research has developed a novel method of reverse engineering some of the syntax of such 4GLs (with Uniface as an exemplar) derived from a particular system, with a view to providing a reliable method to translate/transpile that system's code and data structures into a modern object-oriented language (such as C\#). The method was also applied, although only to a limited extent, to some other 4GLs, Informix and Apex, to show that it was in principle more broadly applicable. A novel testing method that the syntax had been successfully translated was provided using 'abstract syntax trees'. The novel method took manually crafted grammar rules, together with Encapsulated Document Object Model based data from the source language and then used parsers to produce syntactically valid and equivalent code in the target/output language. This proof of concept research has provided a methodology plus sample code to automate part of the process. The methodology comprised a set of manual or semi-automated steps. Further automation is left for future research. In principle, the author's method could be extended to allow the reverse engineering recovery of the syntax of systems developed in other proprietary 4GLs. This would reduce time and cost for the ongoing maintenance of such systems by enabling their software engineers to work using modern object-oriented languages, methodologies, tools and techniques