The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 01, 1998
Filed:
Oct. 27, 1992
Arun N Swami, San Jose, CA (US);
Honesty C Young, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system and method is provided for distributed relational databases for parallel sorting of a relation wherein the relation is a set of tuples to be sorted on multiple sort sites which completely decouples the return phase from the sort phase in order to eliminate the merge phase. The method involves selecting one coordinator site from any of the available logical sites, then generating and sorting a local sample on each of the available storage sites before sending the local random sample from each storage site to the designated coordinator site wherein the local random samples are merged to provide a single global sample. The coordinator site determines the global interval key values based on the global sample. The interval key values being determined such that each interval fits in a single sort site's main memory, wherein the tuples between two interval key values define the interval. The interval key values are sent to the various storage sites wherein each storage site scans its portion of the relation in order to determine for each tuple the assigned interval and its corresponding sort site before sending each tuple to the assigned sort site. At each sort site the tuples are stored in temporary files using a single temporary file for each interval whereafter repeating, for each interval on each sort site, the steps of reading an interval and performing an in-memory sort in any fashion of the interval read before sending the tuples of the sorted interval to the sink site.