This article presents a summary of the main activities of the Database & Information Systems Research Group at Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) and the Information Management Research Group at Universidade Federal de Minas Gerais (UFMG). These two groups played a pioneering role in the development of the information and data management research area in Brazil. The survey covers about four decades of research work, aiming at theoretical and practical results, with increasing participation of other groups that they helped to initiate.

Higher Education Institutions store a sizable amount of data, including student records and the structure of a degree curriculum. This paper focuses on the problem of identifying how closely students follow the recommended order of the courses in a degree curriculum, and to what extent their performance is affected by the order they actually adopt. It addresses this problem by applying techniques to mine frequent itemsets to student records. The paper illustrates the application of the techniques for a case study involving over 60,000 student records in two undergraduate degrees at a Brazilian University.

Quests are a fundamental storytelling mechanism used by computer role-playing games to engage players in the game's narrative. Although role-playing games have evolved in many different ways in the last years, their basic narrative structure is still based on static plots manually created by game designers. In this paper, we present a method for the generation of dynamic quests based on hierarchical task decomposition and planning under non-determinism. The proposed approach combines planning, execution, and monitoring to efficiently handle nondeterministic events and support quests with multiple endings that affect the game's narrative and create interactive and dynamic story plots. These plots are directly or indirectly affected by player's actions and decisions. Furthermore, this paper presents the concept of hierarchical quests.

The development of interactive narratives with the quality of feature films is the central challenge of what we can name Video-Based Interactive Storytelling. A promising approach to this question is the use of prerecorded videos with real actors. Amongst several technical challenges, this approach firstly requires automatic video editing methods for interactive narratives. However, this is a critical issue not fully covered in the literature. In this paper, we present a real-time editing method for interactive storytelling systems, which automatically generates the most adequate shot transitions, swaps video segments to avoid jump cuts, and creates adequate looping scenes. Moreover, these features consider the characteristics of the ongoing story.

Data mashups constructed from independent sources may contain inconsistencies, puzzling the user that observes the data. This paper formalizes the notion of consistent data mashups and introduces a heuristic procedure to compute such mashups.

This paper first proposes a multi-agent architecture to mediate access to data sources. The mediator follows the classical approach to process user queries. However, in the background, it post-processes query results to gradually construct matchings between the export schemas and the mediated schema. The central theme of the paper is an extensional schema matching strategy based on similarity functions. The paper concludes with experimental results that assess the quality of the matching strategy.

Metaphor is not merely a rhetorical device, characteristic of language alone, but rather a fundamental feature of the human conceptual system. A metaphor is understood by finding an analogy mapping between two domains. This paper argues that analogy mappings facilitate conceptual modeling by allowing the designer to reinterpret fragments of familiar conceptual models in other contexts. The contributions of the paper are expressed within the tradition of the Entity-Relation model.

Workflow management systems usually interpret a workflow definition rigidly. However, there are real life situations where users should be allowed to deviate from the prescribed static workflow definition for various reasons, including lack of information, unavailability of the required resources and unanticipated situations. Furthermore, workflow complexity may grow exponentially if all possible combinations of anticipated scenarios must be compiled into the workflow definition. To flexibilize workflow execution and help reduce workflow complexity, this paper proposes a dual strategy that combines a library of predefined typical workflows, of manageable complexity, with a planner mechanism capable of synthesizing more complex workflows, at execution time, tuned to the scenario in question. This dual strategy is motivated by the difficulty of designing emergency plans, modeled as workflows, which account for real life complex crisis or accident scenarios..

A cooperative interface that, using suitable user models, alters the processing of the user's queries to include additional information that will block faulty inferences is described. In a sense, the interface actively teaches the user facts about the database not explicitly asked for. User interaction with the database then becomes a learning and discovery process guided by the queries posed to the interface. A semantics for user models is introduced that captures, with the help of default logic, the nonmonotonic behavior users normally exhibit. Results showing that the cooperative interface generates enough additional information to block all faulty inferences are presented.>

A modularization discipline for database schemas is first described. The dicipline incorporates both a strategy for enforcing integrity constraints and a tactic for organizing large sets of database structures, integrity constraints, and operations. A software tool that helps the development and maintenance of database schemas modularized according to the discipline is then presented. It offers a user-friendly interface that guides the designer through the various stages of the creation of a new module or through the process of changing objects of existing modules. The tool incorporates, in a declarative style, a description of the design and redesign rules behind the modularization discipline, hence facilitating the incremental addition of new expertise about database design.

Formal techniques exist for the crucial specification phase in the design of systems, including database applications. We briefly indicate the potential benefits of the so-called abstract data type discipline and show how it might be made more palatable to the non-mathematician. This is done through the mechanism of traces. This tool is used both as a mechanism for modelling (in an executable manner) the application and as a basis for a methodology which can be used in the development of a formal algebraic specification.

Logical, algebraic, programming language, grammatical and denotational formalisms are investigated with res pect to their applicability to formal data base speci fication. On applying each formalism for the purpose that originally motivated its proposal, it is shown that they all have a fundamental and well integrated role to play in different parts of the specification process. An example is included to illustrate the methodological aspects.

An algebra which operates on partitioned relations is developed. Relation partitioning is achieved by defining equivalence relations on n-ary relations. It is shown that the algebra is as powerful as the original relational algebra, having the advantage of a set-processing capability. This feature provides both greater flexibility in query specification and efficient query processing.