Key Integrity for Cooperative Database Environments with Stationary and Mobile Hosts

ACID properties and serialisability have been extensively studied for transactions that are submitted concurrently in a multithread database environment. A number of protocols have been proposed to ensureACID properties for centralised and distributed databases. These protocols aim to ensure consistency of update operations. However, they do not address key integrity problems that arise in a heterogeneousmultidatabase environmentwhen some of the hosts in the multidatabase have no constant communication links which is a frequently found situation for environments with mobile hosts. Transactions in such environments have longer life time which complicates transaction management and replica control protocols. In this paper we propose to use semantic information from the conceptual schema of the MDBS to ensure key integrity. Transaction handling and reconciliation protocols for entities with natural and surrogate primary keys are proposed and the description of the delayed commit protocol is presented.