A Relationally Complete Visual Query Language for Heterogeneous Data Sources and Pervasive Querying

Abstract

In this paper we introduce and formally define Query by Browsing (QBB), a scalable, relationally complete visual query language based on the desktop user interface paradigm and tuple relational calculus that allows the formulation of complex queries over relational, entity-relationship, object-oriented and XML data sources on a variety of handheld and desktop platforms. It is to our knowledge the first visual query language to combine the important characteristics of usability, scalability, expressive power and flexibility. We support these claims by demonstrating the similarity of the QBB paradigm to the popular desktop user interface paradigm, by relating it to relational calculus and relational algebra and by describing Chiromancer II, a web-based implementation of the QBB paradigm for handheld devices. We also discuss ways in which non-relational sources can be represented and queried and compare QBB to related work in the area of visual query languages for a variety of data models. We finally offer conclusions and thoughts for future work. I. IAs the volume and heterogeneity of data increases, as users become more demanding in their queries and mobile in their workplace and as information is accessed through an increasing variety of devices, the need for better search interfaces becomes imperative. We believe that a modern search interface able to deal with these challenges should be:• Usable: discretionary users should be able to form meaningful queries with little or no instruction and within a reasonable amount of time. • Powerful: queries of arbitrary complexity should be achievable. • Flexible: suitable for a wide variety of domains and data models. • Scalable: able to accommodate large schemas with large amounts of information and adaptable to the diminutive screen size of handheld devices. In this paper we present Query by Browsing (QBB), a Visual Query Language that combines the file browsing features of the desktop user interface paradigm with concepts from the relational model and the expressive power of relational calculus. We begin by describing and formally defining the QBB paradigm. We then demonstrate its expressive power by comparing it to relational algebra and make claims about its usability by presenting its similarity to the widely popular desktop user interface paradigm. We discuss its suitability for presenting and querying non-relational data sources such as entity-relationship, object-oriented and XML schemata. We also compare and contrast it with other query languages in terms of ease of use, expressiveness, flexibility and scalability. We then provide some implementation details regarding Chiromancer II and the QBB paradigm in general. Throughout our discussion, we use screenshots from Chiromancer II, a web-based implementation of the QBB paradigm for handheld devices, thus demonstrating its scalability through its minimal screen requirements. Finally, we present our conclusions and thoughts for future work. II. T QBB The main idea behind the QBB paradigm is to ...

A novel keyword search paradigm in relational databases: Object summaries

“…DBLP [44], IMDB [45]), university (e.g. [46]) databases, etc. Certainly, the consideration of a particular domain theme of a database during attribute clustering in combination with the use of ontologies describing such domains will improve results quality; since it will facilitate finer and more accurate clustering.…”

Expressive Query Construction through Direct Manipulation of Nested Relational Results

“…In diagram-based systems, the user manipulates queries for example through a schema tree or schema diagram, as in Query-by-Diagram (QBD) [6], Query-byBrowsing (QBB) [84], QURSED [81], App2You [66], Related Worksheets [10] and OptiqueVQS [94], or through a diagrammatic query plan, as in VisualTPL [27]. The diagram-based query building style is common in commercial tools-Microsoft Access, Navicat, pgAdmin, dbForge, Alteryx etc.…”

“…The effect is a schema navigation capability analogous to that of QBB [84], AppForge [108], and App2You [66].…”

Query by Templates: Using the Shape of Information to Search Next-Generation Databases

“…Jones uses VQuery, a graphical query interface application that provides an alternative query interface to textual Boolean query specifications and dynamically provides responses to refinements of queries [29]. Other related work in this area includes Query By Browsing (QBB)-a relationally complete visual query language for heterogeneous data sources that uses the desktop paradigm to provide a user interface for querying relational, object-oriented, and XML data sources [30]. Mohan and Kashyap present a visual query language called VQL capable of posing queries on object-oriented databases, using a set of "graphical primitives" along with a set of rules for combining them [31].…”