Title :
A group-select operation for relational algebra and implications for database machine design
Author_Institution :
Dept. of Comput. Sci., Calgary Univ., Alta., Canada
fDate :
1/1/1988 12:00:00 AM
Abstract :
A group-select operation has been defined for relational algebra. This operation is found to be useful for efficiently reducing expressions of nonprocedural relational languages that permit natural quantifiers. Conceptually, the operation first partitions a relation into blocks of tuples that have the same value for an attribute or attribute concatenation. It then extracts each block for which a specified number of tuples meet a specified condition. The quantity of tuples for the operation is specified by means of a natural quantifier. Performance of the group-select operation will be poor with conventional file processing, making the operation more suitable for use with a database machine with an associative memory
Keywords :
relational databases; associative memory; database machine design; group-select operation; natural quantifiers; nonprocedural relational languages; relational algebra; tuples; ANSI standards; Algebra; Associative memory; Calculus; Database machines; EMP radiation effects; Natural languages; Relational databases; Remuneration; Standards development;
Journal_Title :
Software Engineering, IEEE Transactions on
