Clustered Index vs NonClustered Index.

 Posted by Chikul on 12/15/2009 | Category: Sql Server Interview questions | Views: 4394

Clustered Index :
A Clustered index determines the physical order of data in a table and is particularly efficient on columns that are often searched for ranges of values.
The leaf nodes of a clustered index contain the data pages.
There can be only one clustered index per table.
"primary key" is the ideal column for a clustered index
Clustered indexes are good for range searches.

Nonclustered Index :
Nonclustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk.
The leaf node of a nonclustered index does not consist of the data pages. Instead, the leaf nodes contain index rows.
There can be multiple non-clustered indexes per table.
"Unique Key" is the ideal column for a nonclustered index
Non-clustered indexes are good for random searches.

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