Abstract/Details

MATCHING FUNCTIONS AND DISAGGREGATIONS IN DATABASES

ABITEBOUL, SERGE JOSEPH.   University of Southern California ProQuest Dissertations Publishing,  1982. 0550380.

Abstract (summary)

A new algebraic operator, called matching function, is introduced. The composition of matching functions and cartesian products, named an MC-mapping, is then studied. It is shown that the set of all MC-mappings generates the well-known conjunctive queries without constant. A simple algebraic axiomatisation is given for proving containment (and thus equality) between MC-mappings. MC-dependencies are defined as containment between two MC-mappings and shown to be equivalent to non-typed embedded implicational dependencies.

Another algebraic operator, called (X-)disaggregation, which is an inverse of the aggregation described by Smith and Smith, is also introduced. Some general properties of (X-) disaggregation, as well as the closure of particular dependency families under (X-) disaggregation, are investigated. Finally, the closure of free families under matching function, cartesian product, selection and disaggregation, and under subsets of these four operations, is studied. In particular, some special families, i.e., functional dependency families, one-join dependency families and "simple" families, are characterized in terms of closure of free families under some of these operations.

Indexing (details)


Subject
Computer science
Classification
0984: Computer science
Identifier / keyword
Applied sciences
Title
MATCHING FUNCTIONS AND DISAGGREGATIONS IN DATABASES
Author
ABITEBOUL, SERGE JOSEPH
Number of pages
1
Degree date
1982
School code
0208
Source
DAI-B 43/05, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
979-8-204-87016-1
University/institution
University of Southern California
University location
United States -- California
Degree
Ph.D.
Source type
Dissertation or Thesis
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
0550380
ProQuest document ID
303233018
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/docview/303233018