ACM SIGMOD Record

Bestavros, Azer

doi: 10.1145/381854.381860pmid: N/A

Ramamritham, Krithi; Sivasankaran, Raju; Stankovic, John A.; Towsley, Don T.; Xiong, Ming

doi: 10.1145/381854.381868pmid: N/A

Haritsa, Jayant R.; Seshadri, S.

doi: 10.1145/381854.381870pmid: N/A

Kuo, Tei-Wei; Mok, Aloysius K.

doi: 10.1145/381854.381873pmid: N/A

While much recent work has focussed on the performance of transaction systems where individual transactions have deadlines, our research addresses the semantics of data usage in real-time applications and its integration with real-time resource management, in particular, the timeless value of real-time data and the inherent path and not state-based constraints on concurrency control. Central to our research is the idea of similarity which is a reflexive, symmetric relation over the domain of a data object. By exploiting the similarity relation, we propose a class of efficient data-access policies for real-time data objects. We shall also discuss the design of a distributed real-time data-access interface. Our goal is to build a database facility which can support predictable real-time applications involving high-speed communication, information access, and multimedia.

Ulusoy, Özgür; Buchmann, Alejandro

doi: 10.1145/381854.381876pmid: N/A

Lin, Kwei-Jay; Peng, Ching-Shan

doi: 10.1145/381854.381878pmid: N/A

Son, Sang H.; David, Rasikan; Thuraisingham, Bhavani

doi: 10.1145/381854.381879pmid: N/A

Database systems for real-time applications must satisfy timing constraints associated with transactions, while maintaining data consistency. In addition to real-time requirements, security is usually required in many applications. Multilevel security requirements introduce a new dimension to transaction processing in real-time database systems. In this paper, we argue that because of the complexities involved, trade-offs need to be made between security and timeliness. We briefly present the secure two-phase locking protocol and discuss an adaptive method to support trading off security for timeliness, depending on the current state of the system. The performance of the adaptive secure two-phase locking protocol shows improved timeliness. We also discuss future research direction to improve timeliness of secure database systems.

Adelberg, Brad; Kao, Ben; Garcia-Molina, Hector

doi: 10.1145/381854.381882pmid: N/A

We believe that the greatest growth potential for soft real-time databases is not as isolated monolithic databases but as components in open systems consisting of many heterogenous databases. In such environments, the flexibility to deal with unpredictable situations and the ability to cooperate with other databases (often non-real-time databases) is just as important as the guarantee of stringent timing constraints. In this paper, we describe a database designed explicitly for heterogeneous environments, the STanford Real-time Information Processor (STRIP). STRIP, which runs on standard Posix Unix, is a soft real-time main memory database with special facilities for importing and exporting data as well as handling derived data. We will describe the architecture of STRIP, its unique features, and its potential uses in overall system architectures.

Andler, S. F.; Hansson, J.; Eriksson, J.; Mellin, J.; Berndtsson, M.; Eftring, B.

doi: 10.1145/381854.381881pmid: N/A

Silberschatz, Avi; Stonebraker, Mike; Ullman, Jeff

doi: 10.1145/381854.381886pmid: N/A