Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 22 Issue 2, June 1997

Logical design for temporal databases with multiple granularities
X. Sean Wang, Claudio Bettini, Alexander Brodsky, Sushil Jajodia
Pages: 115-170
DOI: 10.1145/249978.249979
The purpose of good database logical design is to eliminate data redundancy and isertion and deletion anomalies. In order to achieve this objective for temporal databases, the notions of temporal types, which formalize time...

On the semantics of “now” in databases
James Clifford, Curtis Dyreson, Tomás Isakowitz, Christian S. Jensen, Richard Thomas Snodgrass
Pages: 171-214
DOI: 10.1145/249978.249980
Although “now” is expressed in SQL and CURRENT_TIMESTAMP within queries, this value cannot be stored in the database. How ever, this notion of an ever-increasing current-time value has been reflected in some temporal...

Applying formal methods to semantic-based decomposition of transactions
Paul Ammann, Sushil Jajodia, Indrakshi Ray
Pages: 215-254
DOI: 10.1145/249978.249981
In some database applications the traditional approach of seerializability, in which transactions appear to execute atomically and in isolation on a consistent database state, fails to satisfy performance requirements. Although many researchers...

An adaptive data replication algorithm
Ouri Wolfson, Sushil Jajodia, Yixiu Huang
Pages: 255-314
DOI: 10.1145/249978.249982
This article addresses the performance of distributed database systems. Specifically, we present an algorithm for dynamic replication of an object in distributed systems. The algorithm is adaptive in the sence that it changes the replication...