Title :
How to extend a conventional optimizer to handle one- and two-sided outerjoin
Author :
Galindo-Legaria, César ; Rosenthal, Arnon
Author_Institution :
Aiken Comput. Lab., Harvard Univ., Cambridge, MA, USA
Abstract :
The authors provide a nearly complete theory for reordering join/outerjoin queries. The theory is used to describe modular extensions that strengthen a conventional optimizer to handle nearly all select/project/join/outerjoin queries. Unlike previous work, these results are not limited to queries possessing a nice structure, or queries that are nicely represented in relational calculus. The theoretical results concern query simplification and reassociation using a generalized outerjoin
Keywords :
database theory; entity-relationship modelling; query processing; relational algebra; relational databases; conventional optimizer; generalized outerjoin; one-sided outerjoin; query processing; query simplification; reassociation; relational calculus; relational database; two-sided outerjoin; ANSI standards; Calculus; Dynamic programming;
Conference_Titel :
Data Engineering, 1992. Proceedings. Eighth International Conference on
Conference_Location :
Tempe, AZ
Print_ISBN :
0-8186-2545-7
DOI :
10.1109/ICDE.1992.213169
