A formal definition of the Users View (UV) of the Graphical Object Query Language (GOQL)

In this paper we provide a brief formal definition of the Users View (UV) of the Graphical Object Query Language(GOQL). The UV provides a graphical representation for object-oriented database schemas and hides from end-users most of the perplexing details of the object-oriented database model, such as methods, hierarchies and relationships. In particular, the UV does not distinguish between methods, attributes and relationships, encapsulates the is-a hierarchy and utilises a number of desktop metaphors to present a graphical schema that is easy to be understood by end-users. Thus, the UV provides the environment, through which end-users, can pose ad-hoc queries through GOQL. We first give a brief formal definition of an object-oriented database schema in the GOQL model. This is given, by providing a formal definition of the basic element of such a schema, namely the class. The UV is then briefly formally defined as a mapping from a GOQL object-oriented database schema. Using this mapping, any object-oriented database schema can be translated into a graphical representation in the UV. The running example of the paper is used to demonstrate the mapping from the textual schema to the graphical schema of the UV. The formal definition of the UV will allow us, in the future, to formally define the graphical constructs of GOQL

Context-Sensitive Control Flow Graph

Control Flow Graph (CFG) is known to be essential in compiler optimizations and quite useful in program comprehension. But visualizing and understanding CFG is hard because the CFG is often too large. The problem becomes harder if one were to understand inter-procedural CFG. Often the user wants to understand specific aspects of the CFG; hence, omitting parts of CFG irrelevant to the user\u27s current interest becomes a desirable approach in working with CFG. We formalize an approach of constructing and visualizing CFG that takes users\u27 interests into account. Users have to specify the program artifacts that are of interest to them, then we define the Context-Sensitive CFG that is relevant to the artifacts. The Context-Sensitive CFG is much smaller in size. The actual compression depends on the context and its spread in the given code. We show some results using the XINU operating system code as the test case. While the Context-Sensitive CFG captures only the relevant details, it could still be of substantial size and complexity. We propose query capability as a next step to help the user by extracting details related to a specific question. For example, the user can apply a query to check if there is an execution path in the CFG along which there is a missing memory deallocation and thus a possible memory leak. This thesis only implements queries that operate solely within the scope of a method (intra-procedural). We have built a proof-of-concept tool that allows the user to visualize Context-Sensitive CFG and make queries

Cognitive Foundations for Visual Analytics

In this report, we provide an overview of scientific/technical literature on information visualization and VA. Topics discussed include an update and overview of the extensive literature search conducted for this study, the nature and purpose of the field, major research thrusts, and scientific foundations. We review methodologies for evaluating and measuring the impact of VA technologies as well as taxonomies that have been proposed for various purposes to support the VA community. A cognitive science perspective underlies each of these discussions

The user's view level of the GOQL graphical query language

The paper addresses issues related to the design of a graphical query mechanism that can act as an interface to any object-oriented database system (OODBS), in general, and the object model of ODMG 2.0, in particular. In the paper a brief literature survey of related work is given, and an analysis methodology that allows the evaluation of such languages is proposed. Moreover, the user's view level of a new graphical query language, namely GOQL (Graphical Object Query Language), for ODMG 2.0 is presented. The user's view level provides a graphical schema that does not contain any of the perplexing details of an object-oriented database schema, and it also provides a foundation for a graphical interface that can support ad-hoc queries for object-oriented database applications. We illustrate, using an example, the user's view level of GOQ