Concurrency control for relational databases

A transaction model for relational databases is presented. The model is more realistic than the traditional entity based model, since it takes into consideration the special information available in the relational model and in the transactions of a given transaction set. Therefore the model can serve as the basis of an implementation, unlike in the present situation, where implementations must rely on ad hoc techniques or physical level concepts. A concurrency control method is developed based on the transaction model. The method is reminiscent of precision locking, but again it is tailored for the relational model. An efficient implementation of the method is outlined.