The theory of joins in relational data bases

Answering queries in a relational database often requires that the natural join of two or more relations be computed. However, not all joins are semantically meaningful. This paper gives an efficient algorithm to determine whether the join of several relations is semantically meaningful (lossless) and an efficient algorithm to determine whether a set of relations has a subset with a lossy join. These algorithms assume that all data dependencies are functional. Similar techniques also apply to the case where data dependencies are multivalued.

[1]  Ronald Fagin,et al.  Multivalued dependencies and a new normal form for relational databases , 1977, TODS.

[2]  Philip A. Bernstein,et al.  Synthesizing third normal form relations from functional dependencies , 1976, TODS.

[3]  Catriel Beeri,et al.  A Sophisticate's Introduction to Database Normalization Theory , 1978, VLDB.

[4]  E. F. Codd,et al.  Further Normalization of the Data Base Relational Model , 1971, Research Report / RJ / IBM / San Jose, California.

[5]  Catriel Beeri,et al.  A complete axiomatization for functional and multivalued dependencies in database relations , 1977, SIGMOD '77.

[6]  E. F. Codd,et al.  A Relational Model for Large Shared Data Banks , 1970 .

[7]  C. Robert Carlson,et al.  A generalized access path model and its application to a relational data base system , 1976, SIGMOD '76.

[8]  Glenn K. Manacher.  On the feasibility of implementing a large relational data base with optimal performance on a minicomputer , 1975, VLDB '75.

[9]  W. W. Armstrong,et al.  Dependency Structures of Data Base Relationships , 1974, IFIP Congress.

[10]  Carlo Zaniolo,et al.  Analysis and design of relational schemata for database systems. , 1976 .

[11]  Alfred V. Aho,et al.  The Design and Analysis of Computer Algorithms , 1974 .

[12]  E. F. Codd,et al.  Recent Investigations in Relational Data Base Systems , 1974, ACM Pacific.

[13]  Robert E. Tarjan,et al.  Depth-First Search and Linear Graph Algorithms , 1972, SIAM J. Comput..

[14]  FaginRonald.  Multivalued dependencies and a new normal form for relational databases , 1977 .

[15]  Philip A. Bernstein,et al.  Comment on "Decomposition of a Data Base and the Theory of Boolean Switching Functions" , 1977, IBM J. Res. Dev..

[16]  Michael Stonebraker,et al.  The design and implementation of INGRES , 1976, TODS.

[17]  C. Robert Carlson,et al.  The Information Preserving Properties of Relational Database Transformations , 1978, VLDB.

[18]  Jorma Rissanen,et al.  Independent components of relations , 1977, TODS.