View-based tool integration in database-centered environments

Abstract

Database-centered environment architectures differ significantly from file-based architectures. Consequently they require a different set of primitives for tool support. This paper describes a form of tool composition called cotools which provides many of the benefits of UNIX pipes in terms of being able to reuse existing tools in tool composites, and allowing tools to operate concurrently ad incrementally on data. However, the tool language and the composition model is tailored to provide these benefits in a database-centered environment where tools do not directly communicate with each other. The effect of communication is achieved by allowing member tools in a cotool to access common data in a coordinated manner while allowing the changes made to data by one tool immediately visible to other tools in the cotool.Since database transactions normally maintain consistency in a database by disallowing interleaved data manipulation amongst separate applications, certain modifications to the concept of transactions are required. One of goals from a systemic point of view is to allow the benefits of tool cooperation without completely violating the transactions idea, which is a very clean mechanism for maintaining data consistency in a shared data store.