Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 4 Issue 2, June 1979

Optimization of query evaluation algorithms
S. Bing Yao
Pages: 133-155
DOI: 10.1145/320071.320072
A model of database storage and access is presented. The model represents many evaluation algorithms as special cases, and helps to break a complex algorithm into simple access operations. Generalized access cost equations associated with the...

Linear queries in statistical databases
M. D. Schwartz, D. E. Denning, P. J. Denning
Pages: 156-167
DOI: 10.1145/320071.320073
A database is compromised if a user can determine the data elements associated with keys which he did not know previously. If it is possible, compromise can be achieved by posing a finite set of queries over sets of data elements and employing...

Optimal partial-match retrieval when fields are independently specified
Alfred V. Aho, Jeffrey D. Ullman
Pages: 168-179
DOI: 10.1145/320071.320074
This paper considers the design of a system to answer partial-match queries from a file containing a collection of records, each record consisting of a sequence of fields. A partial-match query is a specification of values for zero or more...

A Majority consensus approach to concurrency control for multiple copy databases
Robert H. Thomas
Pages: 180-209
DOI: 10.1145/320071.320076
A “majority consensus” algorithm which represents a new solution to the update synchronization problem for multiple copy databases is presented. The algorithm embodies distributed control and can function effectively in the presence...

Locking granularity revisited
Daniel R. Ries, Michael R. Stonebraker
Pages: 210-227
DOI: 10.1145/320071.320078
Locking granularity refers to the size and hence the number of locks used to ensure the consistency of a database during multiple concurrent updates. In an earlier simulation study we concluded that coarse granularity, such as area or file...

Partial-match hash coding: benefits of redundancy
Walter A. Burkhard
Pages: 228-239
DOI: 10.1145/320071.320079
File designs suitable for retrieval from a file of k-field records when queries may be partially specified are examined. Storage redundancy is introduced to obtain improved worst-case and average-case performances. The resulting...

Experiments on the determination of the relationships between terms
Vijay V. Raghavan, C. T. Yu
Pages: 240-260
DOI: 10.1145/320071.320081
The retrieval effectiveness of an automatic method that uses relevance judgments for the determination of positive as well as negative relationships between terms is evaluated. The term relationships are incorporated into the retrieval process...