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Author Yao, S. B.
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Language English
Subject Keyword Inverted file organization ♦ Query answering ♦ Database ♦ Information retrieval ♦ Database performance and measurement
Abstract When data records are grouped into blocks in secondary storage, it is frequently necessary to estimate the number of blocks XD accessed for a given query. In a recent paper [1], Cardenas gave the expression XD = m(1 - (1 - 1/m)k), (1) assuming that there are n records divided into m blocks and that the k records satisfying the query are distributed uniformly among the m blocks. The derivation of the expression was left to the reader as an exercise.
Description Affiliation: Purdue Univ., West Lafayette, IN (Yao, S. B.)
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2005-08-01
Publisher Place New York
Journal Communications of the ACM (CACM)
Volume Number 20
Issue Number 4
Page Count 2
Starting Page 260
Ending Page 261


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Source: ACM Digital Library