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Re: CBO choose full table scan, not index

From: Steve Howard <stevedhoward_at_gmail.com>
Date: Tue, 27 Nov 2007 08:22:40 -0800 (PST)
Message-ID: <a62dc7fc-371e-4ef6-a7a2-3aeb07d63d34@g21g2000hsh.googlegroups.com> 





...it also occurred to me that the cardinality calculated by the
optimizer is exactly the total number of rows /
(column_1_distinct_values * column2_distinct_values)



1071973 / ( 12 * 3) = 29777



It may not help, but it at least pushes you in a direction for the
numbers the optimizer is using.
Received on Tue Nov 27 2007 - 10:22:40 CST












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