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Author Bonnet, Philippe ♦ Kapitskaia, Olga ♦ Raschid, Louiqa ♦ Amouroux, Rémy ♦ Naacke, Hubert ♦ Tomasic, Anthony
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Computer programming, programs & data
Abstract The Distributed Information Search COmponent (DISCO) is a prototype heterogeneous distributed database that accesses underlying data sources. The DISCO prototype currently focuses on three central research problems in the context of these systems. First, since the capabilities of each data source is different, transforming queries into subqueries on data source is difficult. We call this problem the weak data source problem. Second, since each data source performs operations in a generally unique way, the cost for performing an operation may vary radically from one wrapper to another. We call this problem the radical cost problem. Finally, existing systems behave rudely when attempting to access an unavailable data source. We call this problem the ungraceful failure problem.DISCO copes with these problems. For the weak data source problem, the database implementor defines precisely the capabilities of each data source. For the radical cost problem, the database implementor (optionally) defines cost information for some of the operations of a data source. The mediator uses this cost information to improve its cost model. To deal with ungraceful failures, queries return partial answers. A partial answer contains the part of the final answer to the query that was produced by the available data sources. The current working prototype of DISCO contains implementations of these solutions and operations over a collection of wrappers that access information both in files and on the World Wide Web.
Description Affiliation: Bull, Grenoble, France (Amouroux, Rémy; Bonnet, Philippe) || INRIA Rocquencourt, Rocquencourt, France (Tomasic, Anthony; Kapitskaia, Olga; Naacke, Hubert) || University of Maryland, College Park, Maryland (Raschid, Louiqa)
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1999-06-01
Publisher Place New York
Journal ACM SIGMOD Record (SGMD)
Volume Number 26
Issue Number 2
Page Count 3
Starting Page 546
Ending Page 548


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Source: ACM Digital Library