State-conditioned semantics in databases

Abstract

Integrity constraints are usually modeled based on the assumption that they are valid in any database state. This approach underdetermine integrity constraints, leads to strong influence of exceptions and requires complex operational support. However, for operating databases finer granularity in integrity and operational modeling is required. This paper proposes dynamic state-oriented modeling of integrity constraints. It has several advantages over other approaches: modeling is simpler; exceptions are modeled together with states; integrity maintenance is simpler; modeling granularity is higher; incorrect operations can be corrected; generic operations have greatest consistent specializations; parallelism is supported. Further, transactions can be distinguished into state preserving transactions and state transformation transactions. This distinction supports specialized handling of special transactions.