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From: RG on 2 May 2010 11:47
It appears that outside of statistcs name, sql server allows you to
create duplicate statistics. How does sql server handle statistics
update when this happens?

Also, is there a difference in having single create statistics
statement for two columns compared to two create statistics statements
for one column each?

Thanks in advance

From: Erland Sommarskog on 2 May 2010 12:37
RG (nobody(a)nowhere.com) writes:
> Also, is there a difference in having single create statistics
> statement for two columns compared to two create statistics statements
> for one column each?

There is a big difference. SQL Server maintains a distribution histogramme
only for the top column in the statistics. For remaining columns there is
only density information.



--
Erland Sommarskog, SQL Server MVP, esquel(a)sommarskog.se

Links for SQL Server Books Online:
SQL 2008: http://msdn.microsoft.com/en-us/sqlserver/cc514207.aspx
SQL 2005: http://msdn.microsoft.com/en-us/sqlserver/bb895970.aspx
SQL 2000: http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx

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