KeyIsUnique Property

Gets a value that indicates whether the key used in this index is a unique key for the collection.

Syntax

Visual Basic
C#

'Declaration
 
Public ReadOnly Property KeyIsUnique As System.Boolean

public System.bool KeyIsUnique {get;}

Property Value

true if the key is unique; otherwise, false

Remarks

A unique index occupies less memory and performs better than a non-unique index (although the difference isn't dramatic). Therefore, for unique keys, it's recommended to specify the corresponding index as unique in the IndexCollection.Add method.

But do that only if you are sure that the key is indeed unique, as it imposes a uniqueness constraint on the collection. An attempt to modify the collection violating the uniqueness throws an System.InvalidOperationException.

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

IndexDefinition<T> Class
IndexDefinition<T> Members