Index Concurrency Control in Firm Real-Time DBIM:S

Although real-time transaction concurrency control has been extensively studied, the design and evaluation of real-time in&l: concurrency control algorithms has not yet been considered. In this paper, we develop real-time variants of several classical B-tree concurrency control algorithms and compare their performance using a detailed simulation model of a firm-deadline real-time database system. The experimental results show that the performance characteristics of the real-time version of an index concurrency control algorithm could be significantly different from the performance of the same algorithm in a conventional (non-real-time) database system. In particular, B-link algorithms, which are reputed to provide the best overall performance in conventional database systems, perform poorly under heavy real-time loads. We Permission to copy without fee all OT paTt of this material is granted provided that the copies are not made OT distributed for direct commercial advantage, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Very Large Data Base Endowment. To copy otherwise, OT to republish, requiTes a fee and/or special permission from the Endowment. Proceedings of the 21st VLDB Conference Zurich, Switzerland, 1995 present and evaluate a simple load-adaptive variant of the B-link algorithm called LABlink, which provides the best performance over the entire loading range for a variety of realtime transaction workloads.