abstraction for modeling these problems is to view the Web as a collection of (usually small and heterogeneous) databases, and to view programs that extract and process Web data automatically as database applications (see Balasubramanian and Bashian; Kambil and Ginsburg, both in this issue). The WebOQL system [2], developed at the University of Toronto, is a tool for building the software layer through which such programs can view Web data in a uniform, convenient format and can effectively manipulate it using a declarative query language. To accomplish this uniformity, WebOQL synthesizes ideas from several areas of research [1, 3–5]. As opposed to traditional database models, WebOQL does not require the a priori definition of a schema for the data to be queried, thus making it possible to model irregularly structured data or data with a structure that is only partially known and making it easy to accommodate different kinds of data, such as structured documents, relational tables, a...
Gustavo O. Arocena, Alberto O. Mendelzon