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Go Back  dBforums > General > Database Concepts & Design > relation cardinality/selectivity (was "A difficult question, need help")

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Old 01-09-05, 15:20
weiss_adler weiss_adler is offline
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Exclamation relation cardinality/selectivity (was "A difficult question, need help")
Given is a relation R (A1,A2, A3) with three attributes!
c (A2) = 2 c: cardinality
s (A2) = 64 s: selectivity
An index (binary tree) is created for A2!
What is the depth of a binary tree T(A2) in best case?
What is the depth of a binary tree T(A2) in worst case?
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Old 01-09-05, 16:33
Pat Phelan Pat Phelan is offline
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Assuming you are using the standard definitions for cardinality and selectivity or a relation, the specified relation can't exist, so both answers are NULL.

-PatP
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