Simple description of SQL Server three index and its use

Brief introduction:

1, unique: Unique index, the value of each record of the field cannot be duplicated.

2. Clustered: A clustered index, which can contain more than one column, is faster than a nonclustered index, but only one per table.

3, nonclustered: Nonclustered index, single use, can improve the retrieval performance, but will increase the data stored on the hard disk, that is, the space to change the time

How to use:

CREATE [UNIQUE] [CLUSTERED | Nonclustered] INDEXindex_name on <table_name>(column_name[ASC | DESC] [,... N] )       [With <backward_compatible_index_option> [,... n] ]      [On {filegroup_name | "Default"}]  

A simple example:

Create Clustered Index OPDE_BIID_CD  on Opde (BIID)

Usage Recommendations:

Simple description of SQL Server three index and its use