The Z notation: a reference manual
The Z notation: a reference manual
Set-oriented production rules in relational database systems
SIGMOD '90 Proceedings of the 1990 ACM SIGMOD international conference on Management of data
Descriptive specification of database object behaviour
Data & Knowledge Engineering
Fundamentals of database systems (2nd ed.)
Fundamentals of database systems (2nd ed.)
Concurrent rule execution in active databases
Information Systems
Distributed events in active database systems: letting the genie out of the bottle
Data & Knowledge Engineering - Special jubilee issue: DKE 25
Supporting update propagation in object-oriented databases
Data & Knowledge Engineering
A general treatment of dynamic integrity constraints
Data & Knowledge Engineering
A relational model of data for large shared data banks
Communications of the ACM
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Foundations of Semantic Databases
Foundations of Semantic Databases
Active Database Systems: Triggers and Rules for Advanced Database Processing
Active Database Systems: Triggers and Rules for Advanced Database Processing
Discrete Mathematics in Computer Science
Discrete Mathematics in Computer Science
Implementing High Level Active Rules on Top of a Relational DBMS
VLDB '92 Proceedings of the 18th International Conference on Very Large Data Bases
ILPS '97 International Seminar on Logic Databases and the Meaning of Change, Transactions and Change in Logic Databases
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While specifications of queries usually are of a declarative nature (since the work of Codd in the early seventies), specifications of transactions mainly are of an operational and descriptive nature. Especially descriptions of complex transactions (such as cascading deletes) tend to be very operational. Declarative specifications of transactions usually suffer from the so-called frame problem or do not have a clear semantics. Often these descriptions turn out to be nondeterministic as well. A problematic consequence is that the semantics of transactions and of several related notions is often unclear or even ambiguous. For a database designer this surely is not a good starting point for building applications. Another tendency we recognize is that the current literature on transactions is mainly driven by technical solutions offered by research prototypes and commercial systems and not so much by advanced specification requirements from a user's or database designer's point of view. In our opinion, the research questions should (also) include what kind of complex transactions (advanced) users would like to specify (and not only what e.g. the expressive power of a given technical solution is), and how these specifications can be translated to implementations in the currently available (advanced) database management systems. And, moreover, was it not our purpose (with the introduction of 4GL's and the like) to become declarative instead of operational, concentrating on the "what" instead of the "how"? This paper offers a general framework for declarative specifications of transactions, including complex ones. Transactions on a state space u are considered as functions from u into u. We also take the influence of static and dynamic constraints on the alleged transactions into account. This leads to the notion of the adaptation of a transaction. Applications of our theory included in this paper are the declarative specification of cascading deletes and the distinction between allowable and available transitions. Basic set theory is our main vehicle.