Monday, March 10, 2008

what are index?

Indexs help sql server locate data.they speed up the data retrieval by pointing sql server to the location of table column;’s data on disk.There are tow type of index.

Clustered index-clustered index force sqlserver continually sort and re-sort the rows of table so that physical order is always Same as the logical order.you cab have only one cluster index per table.

Non_cluster index-Do not require the physical order of rows to be the same as their index order.each non clusterd index can provide access to the data in a different order.you can have 249 nonclusterd index per table

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