Transaction mechanisms for software environment databases

Databases for software environments have a set of requirements that are fundamentally different from conventional databases. Besides requiring an object-oriented or semantic data model, CASE databases need to support interactive design transactions, trigger facilities and a application model for integrating software tools. Design transactions are necessary for interactive applications where the duration of a transaction may last days or months. Triggers are useful for incremental data derivation and constraint maintenance. Composite tools, built by reusing tool components, require a multithreaded transaction facility where changes made by one member tool are immediately visible to other members, and the entire complex tool executes as one transaction. The authors describe design transactions, multithreaded transactions, the interaction between the transaction model and triggers, and the rationale for including these features in an environment database