PRECISO

A Reverse Engineering Tool to Discover Web Services from Relational Databases

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PRECISO TOOL

Motivation

The Recovery Process

The Architecture

Tool Demo:

Motivation

Today, organizations are increasingly forced to share more and more information as part of the basic activity in their daily operations. However, the heterogeneity of Information Systems (IS) is growing every day due to the appearance of new technological paradigms, standards, and environments, making it more and more difficult to share information. Due to these facts and in order to keep their competitiveness level throughout their IS, organizations must be involved in a process of continuous renewal. Therefore, IS developers must constantly and quickly develop and maintain their products in order to meet market requirements. Among all the artefacts that compose information systems, databases are possibly one of the most important elements since they contain all the organizational information and form the basis of decision-making. PRECISO is a tool for database re-engineering following the MDA (Model-Driven Architecture) principles to extract Web Services (WS) that show the database as a set of services, offering easy access to the information. PRECISO offers several benefits:

PRECISO minimizes heterogeneity problems since databases can be integrated in SOA environments.
PRECISO also advocates the reuse of legacy databases, thus extending the lifecycle of databases.
PRECISO shortens development time because the WS generation is automatic and instantaneous.

The Recovery Process

The database re-engineering process consists of three main activities broken down into several tasks. DMR is the first activity to create a PSM (Platform-Specific Model) which represents the input relational database. The DMR-1 task recovers metadata from the database and builds the PSM according to an SQL-92 metamodel. The DMR-2 task simultaneously discovers the potential services by means of pattern matching. Each patterns recognized in the database schema is related to specific service templates.

the recovery process

The second activity is OMG, which generates an object model from the previous database schema model. Thus, the OMG-1 task transforms the PSM into a PIM (Platform-Independent Model) according to the UML2 metamodel. Finally, the third activity is WSG, which generates the WS to manage the input database. The WSG-1 task builds the service interfaces in WSDL (Web Services Description Language) from services discovered in DMR-2. This set of interfaces is the target PSM since it represents the WS platform. At the same time, WSG-2 generates the source code related to the object model. This code supports the business layer of WS. Then WSG-3 writes out the source code of the WS. After that, WSG-4 carries out the Web Services deployment. Finally, the WS are ready to be used.

The Architecture

The PRECISO tool automates several tasks in the recovery process; but it also addresses other necessary issues such as remote database connection, connections to databases from different vendors, project management, graphic display of involved models, testing, reporting, and so on. The proposed architecture takes into account the previous challenges.

the architecture of PRECISO

The most important features of PRECISO are:

�project-oriented nature� because it manages a repository with all recovery information.
�partitioned and ordered process generation� since PRECISO generates WS by means of individual, but complementary modules.
�usage of standards� such as SQL-92, XMI (XML Metadata Interchange) and WSDL. Therefore, PRECISO can be integrated with other reverse engineering tools in the market.
�high development process coverage� since it supports metadata extraction, model generation, graphic visualization of models, model transformations, editing and publication of WS, deployment, testing, reporting, and so on.