Abstract
In processing distributed relational database queries, the cost of communication between sites is the dominant cost factor. It is generally agreed that the amount of data transferred determines this communication cost to a large extent. Thus it is desirable to minimize the amount of transmitted data.Semi-join is a relational database operator which can be utilized to reduce the amount of data transmission in processing distributed queries. A class of queries, called tree queries, can always be answered using semi-joins. In this paper an algorithm is presented which decides whether or not a query involvingjoin clauses with relational operators {<≥,≠,≡,≤,>} is a tree query. For any tree query the algorithm also produces a tree query graph, so that the sequences of semi-joins to answer the query can immediately be determined.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: INFOR: Information Systems and Operational Research
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
