Abstract. Software developers adapt to the fast-moving nature of software systems with agile development techniques. However, database developers lack the tools and concepts to keep pace. Data, already existing in a running product, needs to be evolved accordingly, usually by manually written SQL scripts. A promising approach in database research is to use a declarative database evolution language, which couples both schema and data evolution into intuitive operations. Existing database evolution languages focus on usability but did not aim for completeness. However, this is an inevitable prerequisite for reasonable database evolution to avoid complex and error-prone workarounds. We argue that relational completeness is the feasible expressiveness for a database evolution language. Building upon an existing language, we introduce CoDEL. We dene its semantic using relational algebra, propose a syntax, and show its relational completeness.
BiDEL is shown to be relationally complete REF and bidirectional.
CoDEL – A Relationally Complete Language for Database Evolution
Lecture Notes in Computer Science
Lecture Notes in Computer Science
Computer Science