IMPLEMENTATION OF TRANSACTION AND CONCURRENCY-CONTROL SUPPORT IN A TEMPORAL DBMS

Transactions and concurrency control are significant features in datab ase systems, facilitating functions both at user and system level. How ever, the support of these features in a temporal DBMS has not yet rec eived adequate research attention. In this paper, we describe the tech niques developed in order to support transaction and concurrency contr ol in a temporal DBMS that was implemented as an additional layer to a commercial DBMS. The proposed techniques make direct use of the trans action mechanisms of the DBMS. In addition, they overcome a number of limitations such as automatic commit points, lock release and log size increment, which are imposed by the underlying DBMS. Our measurements have shown that the overhead introduced by these techniques is neglig ible, less than 1% in all cases. The approach undertaken is of general interest, it can also be applied to non-temporal DBMS extensions. Cop yright (C) 1998 Elsevier Science Ltd. All rights reserved.