Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 12 Issue 1, March 1987

The partition model: a deductive database model
Nicolas Spyratos
Pages: 1-37
DOI: 10.1145/12047.22718
We present a new database model in which each attribute is modeled by a family of disjoint subsets of an underlying population of objects. Such a family is called a partitioning, and the set of all partitionings is turned into a lattice by...

Associative searching in multiple storage units
C. T. Wu, Walter A. Burkhard
Pages: 38-64
DOI: 10.1145/12047.12048
A file maintenance model, called the multiple random access storage units model, is introduced. Storage units can be accessed simultaneously, and the parallel processing of an associative query is achieved by distributing data evenly among the...

Partial expansions for file organizations with an index
David B. Lomet
Pages: 65-84
DOI: 10.1145/12047.12049
A new way to increase file space in dynamically growing files is introduced in which substantial improvement in file utilization can be achieved. It makes use of partial expansions in which, instead of doubling the space associated with some...

Database performance evaluation in an indexed file environment
Jane Fedorowicz
Pages: 85-110
DOI: 10.1145/12047.13675
The use of database systems for managerial decision making often incorporates information-retrieval capabilities with numeric report generation. Of great concern to the user of such a system is the response time associated with issuing a query...

A new normal form for nested relations
Z. Meral Ozsoyoglu, Li-Yan Yuan
Pages: 111-136
DOI: 10.1145/12047.13676
We consider nested relations whose schemes are structured as trees, called scheme trees, and introduce a normal form for such relations, called the nested normal form. Given a set of attributes U, and a set of multivalued...