SuiteDBDoc: Free Software for Teaching Databases

FINTDI 2009 173 SuiteDBDoc: Free Software for Teaching Databases Piedad Garrido, Francisco J. Martinez, Fernando Naranjo, Inmaculada Plaza, Jesús Tramullas University of Zaragoza Email: {piedad, f.martinez, fnaranjo, iplaza, tramulla}@unizar.es Abstract SuiteDBDoc is a software suite specially designed to improve teaching of the Relational Database Management Systems (RDBMS), that has been developed in the University of Zaragoza (Spain). The suite includes three ad-hoc software tools (ACAR, Anacon, and DEREditor) which provide coverage to the syllabus and the evaluation activities of two subjects: (i) Database I, and (ii) Database II. The software tools presented allow students to learn important database concepts without geographical barriers (distance learning), and these tools are non dependent of any commercial RDBMS software or any Operating System since they are opensource and multi-platform. Moreover, they accomplish the manipulation standard programming languages (Relational Algebra (RA), Tuple Relational Calculus (TRC), and Standard Query Language (SQL)). Results demonstrate that students are pleased to use the suite, and the academical results obtained the last years have improved significantly, where the number of students that passed both database subjects has increased by 30%. I. INTRODUCTION This work presents a project known as SuiteDBDoc that has been developed in the University of Zaragoza (Spain). SuiteDBDoc is a software suite specially designed to improve teaching of the Relational Database Management Systems (RDBMS). The suite includes three ad-hoc software tools (ACAR, Anacon, and DEREditor) which provide coverage to the syllabus and the evaluation activities of two subjects (i) Database I, and (ii) Database II. This project took part in a development of innovation and improvement teaching experience at the University of Zaragoza [1]. The proposal was very interesting for several reasons: (i) the future adaptation of our studies to the European Higher Education Area (EHEA), (ii) the convergence of existing subjects such as Trabajo Fin de Carrera (TFC), Database I, and Database II that appear in the technical computing engineering curricula, and (iii) the design and implementation of a tool that will be used in a real academical environment. Moreover, this project allowed the assessment and implementation of new active and collaborative teaching methodologies. For the analysis, design and implementation of the tools a multidisciplinary workgroup was created. It was made up by members of the whole university community (Administration and Services Personnel (ASP), Teaching and Research Personnel (TRP), and students), with the aim of overcoming the barriers that exist among the different groups, integrating them into a unique system. The experience resulted exceptionally positive. The current database syllabus is divided into two parts, the first one is centered in the use of Database Manipulation Languages (DMLs) and the second one is oriented to the database design, known as Database Definition Languages (DDLs). The objectives of both parts are founded in the Relational Database Model (RDM) work philosophy, based on the Entity-Relation Model [2], [3]. From this perspective, the presented project tries to be a valid framework for the teaching of database subjects, in disciplines with on-site and distance students which involves technical engineering, social-humanistic environment and the University of Experience (UEZ) [4]. Moreover, SuiteDBDoc will make easier the process of adaptation of these subjects to the European Higher Education Area (EHEA, also known as EEES in Spain). This paper is organized as follows: Section II details the goals pursued by this project. In section III, we present the tools that have been developed. Section IV presents the academical results obtained when using the developed software. Finally, Section V concludes this paper. II. OBJECTIVES In this section we present the most important objectives of the SuiteDBDoc project as well as some important remarks. The developed software aims to: Adapt easily our studies at the European Higher Education Area, an European initiative to create more comparable, compatible and coherent systems of higher education. Make possible teaching RDBMS to on-site students and distance learners since subjects can be available on-line. Evaluate the students in the laboratory instead of making a theoretical exam. Ease long-life learning since the students of University of Experience of Zaragoza (UEZ) can study these subjects. The UEZ is a novel initiative that allows elderly people to join the University. Follow a transdisciplinary approach. This kind of approach requires the team members to share roles and systematically cross discipline boundaries. Bruder describes this approach in more detail in [5]. Develop original computer programs applying workgroup methodologies. Although these kind of methodologies are commonly applied in Companies, they are rarely used in Universities. Open the debate to decide if the analysis, design and implementation of application programs must be

174 FINTDI 2009 TABLE I A BRIEF DESCRIPTION OF THE TOOLS Tool Name Framework Development License Description A Relational Algebra (RA), Tuple Relational Calculus ACAR Java and MySQL GNU GPL (TRC), and Standard Query Language (SQL) compiler against MySQL databases. Anacon Kylix Borland/TrollTech license A SQL evaluation tool. The queries must be executed against any RDBMS. Fourth generation database designer and code-generator DerEditor 1 Java GNU GPL for educational purposes and speeding-up database design and creating work. recognized and considered as a new teaching competence. Motivate students since the learning system is being enriched. Increase the academical performance of the students since the developed tools can considerably reduce the required time to do practical lessons. Demonstrate that the development and use of these tools increase the quality and efficiency, opposite to other techniques applied previously. III. DESCRIPTION OF THE TOOLS SuiteDBDoc is a software suite specially designed to improve teaching of the Relational Database Management System (RDBMS). It is made up of three ad-hoc software tools (ACAR, Anacon, and DEREditor) which provide coverage to the syllabus and the evaluation activities of two subjects: (i) Database I, and (ii) Database II. Database I explains how to manipulate RDBMS and the programs used are ACAR and Anacon; ACAR is an automatic query translator, and Anacon is a SQL evaluation tool without any commercial database engine dependencies. Database II covers RDBMS design and implementation, and its computing support is DEREditor. In this section we present all these programs, emphasizing their most relevant characteristics. All these tools are distributed under GNU/GPL licence, i.e., the whole of them are free software at university community disposal. A. ACAR ACAR (Analizador de Consultas en Álgebra relacional) is a Computer-Aided Software Engineering (CASE) development tool which generates, from a query or requirement designed in Relational Algebra (RA), its automatic translation into the Tuple Relational Calculus (TRC) and subsequently into the Structured Query Language (SQL). This computer program advises the students throughout their practical lessons specially about the Database Manipulation Languages (DML) module. The objectives of this ad-hoc software are: (i) to make easier the comprehension of the different DMLs, which can be used to query the information systems, and (ii) to have a compiler which allows the translation and syntactic analysis of the queries in real time and transparent to users. Figure 1 shows the Graphical User Interface (GUI) of ACAR. 1 Available at http://dereditor.sourceforge.net/. Fig. 1. GUI of ACAR application software. Although there are available other free software tools such as LEAP RDBMS [6], RelationalQuery [7], and WinRDBI [8] which have similar functionalities, they have shortcomings which are addressed by ACAR. WinRDBi works with the three DMLs previously commented (i.e., RA, TRC, and SQL), it is multiplatform and free of charge but it has the drawback that it is founded on the basis of established deductive database technology that uses a logic language (Amzi! Prolog and Logic Server [9]) to query the database instance stored as logical facts, so the student has to learn this new language. LEAP RDBMS has been developed to build and compile only Relational Algebra queries and it is very difficult that it will incorporate other manipulation languages in a near future. Finally, RelationalQuery is under development and uses WinRDBI files to execute the queries, so the student has also to learn an additional language. In [10] and [11], authors presented two different comparative studies of free software tools with similar functionalities than ACAR. With ACAR the students have at their disposal the operators graphically as they have been shown in theoretical lessons, so they do not need to know the logic language that uses the compiler, making the learning process easier.

FINTDI 2009 175 Fig. 2. GUI of Anacon. B. Anacon Anacon (Analizador de Consultas SQL) [12] is a SQL query analyzer which allows the students to learn quickly and intensively how to build queries in this language, without requiring to know the complexity and the special features that usually present the commonly used query analyzers, which are usually integrated into the Relational Database Management Systems (RDBMS). Anacon is a free multiplatform software, its interface is in Spanish, and it can connect to the majority of the RDBMS easily (i.e., it is not necessary to make use of any JDBC or ODBC driver). This makes the application software independent and different from the rest of the query analyzers. The student s in class acquired knowledge can be put in practice faster and easier than using other available tools for our students. It makes the application software independent and different from the rest of the query analyzers that are distributed strictly linked to the database software. Figure 2 presents the GUI of Anacon. After installing and testing similar tools such as WinSQL [13], WinRDBI, Active Visual Query Builder [14], and The Query Tool [15], we can conclude that they cannot accomplish exactly with our desired requirements: (i) their graphical user interfaces are complex, (ii) they usually require high knowledge at user level, (iii) most of them are not freely distributed, and (iv) in general, they are not multiplatform (i.e., they only work in Windows systems). Moreover, all of them are distributed in English, and we would prefer a tool with an interface in Spanish that can be used easily for our students without wasting their time due to they are not skillful in English. C. DEREditor DEREditor [16] is a CASE computer program with a visual interface to design Entity-Relationship Diagrams (ERDs). Figure 3 shows the GUI of DerEditor. The main functionalities that the application software provides, are the following: Entity-Relationship diagrams management. The user can create, manage, print and convert to an image, the designs obtained. Assistance to the Entity-Relationship modeling method, used to produce a type of conceptual schema or semantic data model of a system, with the aim of being used for whatever user as easy as possible. Generation of code. It can generate descriptive language, conceptual data language (a pseudocode standard) and SQL. All of it automatically and with utterly usertransparency based on the corresponding ERD. Figure 4 depicts an example of code generated by DEREditor. This tool can also write a description of the information system that can be used as a wording of a practical lesson. So, this tool is thought to be used to teaching the Database II subject which is more centered in the design of Information Systems. The aims of this visual application are: (i) to made easy the comprehension of the different design information system phases (conceptual, logic, and physical design) before it can be processed by a computer, (ii) to allow the graphical visualization of both the conceptual and logic schemes, and (iii) to generate automatically the code associated to each one of the objects represented graphically, in real time and with utterly user-transparency.

176 FINTDI 2009 Fig. 3. GUI of DEREditor. Fig. 5. DEREditor preferences box. Fig. 4. An example of code generated by DEREditor. Similar tools are compared in [16] (DBDesigner [17], DeZign [18], and XCase [19]). All of them have two clear drawbacks: (i) they do not adjust to the Entity- Relation diagram, and (ii) the majority of these tools generate dependable code to the most popular programming languages of the market. Moreover, they require a high level knowledge of the matter, making very difficult to use them in an educational environment, especially in its first learning phases. Table II shows a comparison of the different applications which can be used to manage ERDs.

FINTDI 2009 177 TABLE II A COMPARISON OF THE DIFFERENT APPLICATIONS TO MANAGE ERDS IV. RESULTS In order to demonstrate how the use of the developed tools would affect to the database subjects and their students, we used Anacon and ACAR in Database I, and DEREditor in Database II. We divided the practical groups of each subject into two subgroups. One of them made the practical lessons using the traditional tools (Microsoft Access, SQL-Server, MySQL, OpenOffice.org Base, and Oracle), and the other subgroup used Anacon, ACAR and DEREditor (described in section III). For all the subgroups, students invested some sessions to familiarize with the environment. We saw that students that used traditional tools needed more time to start working their practical lessons since these software packages have a lot of extra functionalities (management, backups, import and export data, etc.); the SQL queries have to be built and compiled throughout the query analyzer and the Entity-Relationship diagram via the System Administrator. Moreover, in the rest of DMLs (RA and CRT) students had to put them into practice in the paper, as none of the computer programs mentioned before have compilers for the execution of this kind of queries or requirements. However, students that used the SuiteDBDoc tools showed a faster adaptation to correctly manage them and they follow their practical lessons easily, in a more independent way. The results showed that students which work with these tools (i) are more motivated, (ii), the pass rate is higher, (iii) the drop out rate is null, (iii) the assistance to practical lessons has been increased (since assistance is not compulsory, it is an important item), and (iv) the average mark is higher in the subgroups that used Anacon, ACAR and DEREditor. This has been reflected in the academical results obtained last year, where the number of students that passed both subjects has increased by 30%. V. CONCLUSION AND FUTURE WORK Students are pleased to have the opportunity to test by themselves the queries and the designs made during the academic year, without investing time to familiarize with the environment or turning to the teacher for their checking. On the one hand, students have at their disposal an access free learning system available in Spanish language, without geographical barriers, independent to commercial RDBMS software, multiplatform, and according to manipulation standard programming languages (RA, CRT, and SQL). The suite allows them to prepare the programme subjects in a practical way, adjusted to the syllabus, and everywhere, quite the opposite methodology to the software previously used (SQL-Server, Microsoft Access, MySQL, etc.), where the student had to learn different environments, and there were license problems. On the other hand, TRPs, ASPs and students have achieved a transdisciplinary approach so the communication style involved continuous give-and-take between all members on a regular, planned basis. Hence, professionals from different disciplines can teach, learn and work together to accomplish a common set of goals. As for the future work, Anacon will incorporate support for DDLs and Entity-Relationship Diagrams to query databases using DMLs. ACAR, currently only works with MySQL, so its functionalities can be extended by supporting additional RDBMS. Moreover, reverse engineering will be added since now the automatic translation must be in this order: RA to CRT, and thereafter CRT to SQL. DEREditor could also incorporate reverse engineering, a database engine, a section of manually adding code, and it would be interesting to increase the supported export formats. Finally, we would like to comment that the current SuiteDBDoc release is under an innovative quality evaluation study that aims to obtain feedback from users, which will let us to improve the suite in the next versions, in order to offer students quality education [20].

178 FINTDI 2009 ACKNOWLEDGMENT The authors would like to thank the University of Zaragoza for its educational innovation helps throughout the last eight years. REFERENCES [1] Proyecto TORICO. Programa de Enseñanza Semipresencial de la Universidad de Zaragoza. Línea de Actuación: Utilización de las TIC en metodologías activas, Universidad de Zaragoza, 2006. [2] C. Date, Introducción a los Sistemas de Bases de Datos. Upper Saddle River, NJ: Prentice Hall, 2001. [3] M. Celma, J. Casamayor, and L. Mota, Bases de Datos Relacionales. Upper Saddle River, NJ: Prentice Hall, 2003. [4] P. Garrido and J. Tramullas, Integración de una disciplina con competencias sociales en el EEES, el Anillo Digital Docente y la Universidad de la Experiencia, in Proc. 8th. International Symposium on Computers in Education (SIIE 06), León, Spain, October 2006, pp. 431 438. [5] M. Bruder, Working with members of other disciplines: Collaboration for success, M. Wolery and J. Wilbers, Eds. Washington, DC: National Association for the Education of Young Children, 1994. [6] R. Leyton. (2009) LEAP RDBMS. [Online]. Available: http://leap.sourceforge.net/ [7] CollabNet, Inc. (2009) RelationalQuery. [Online]. Available: https://relationalquery.dev.java.net/ [8] (2009) WinRDBI. [Online]. Available: http://www.eas.asu.edu/ winrdbi/ [9] Amzi! Inc. (2009) Amzi! [Online]. Available: http://www.amzi.com/ [10] J. Gutiérrez, M. Escalona, D. Villadiego, and M. Mejías, Comparativa de herramientas para la enseñanza de lenguajes relacionales, in Proc. XI Jornadas de Enseñanza Universitaria de la Informática (JENUI 05), Madrid, Spain, July 2005, pp. 297 304. [11], Herramientas libres para enseñanza de álgebra relacional, in Proc. I Congreso Español de Informática (CEDI 05), Granada, Spain, September 2005. [12] P. Garrido, F. Martinez, J. Tramullas, and G. Fuertes, ANACON: Analizador de Consultas SQL, Revista Iberoamericana de Educación a Distancia, RIED, vol. 10, no. 1, pp. 201 215, 2007. [13] Synametrics Technologies. (2009) WinSQL. [Online]. Available: http://www.synametrics.com/synametricswebapp/winsql.jsp [14] ActiveDBSoft. (2009) Active Query Builder. [Online]. Available: http://www.activequerybuilder.com/ [15] Tyson Software. (2009) The Query Tool. [Online]. Available: http://www.tysonsoftware.co.uk/ [16] P. Garrido, M. Coll, and F. Martinez, DerEditor4GL: Software para la docencia de diseño de Bases de Datos, in Proc. XI Jornadas de Enseñanza Universitaria de la Informática (JENUI 05), Madrid, Spain, July 2005, pp. 129 136. [17] fabforce.net. (2009) DBDesigner. [Online]. Available: http://fabforce.net/dbdesigner4/ [18] Datanamic. (2009) DeZign. [Online]. Available: http://www.datanamic.com/dezign/ [19] Resolutin Software Ltd. (2009) XCase. [Online]. Available: http://www.xcase.com/ [20] I. Plaza, R. Igual, J. Marcuello, S.Sánchez, and F. Arcega, Proposal of a quality model for educational software, in Proc. XX Annual Conference of the European Association for Education in Electrical and Information Engineering (EAEEIE 09), Valencia, Spain, June 2009.