QueryExpression.NoLock Property

Article
06/20/2014

Applies To: Microsoft Dynamics CRM 2013, Microsoft Dynamics CRM Online

Gets or sets a value that indicates that no shared locks are issued against the data that would prohibit other transactions from modifying the data in the records returned from the query.

Namespace: Microsoft.Xrm.Sdk.Query
Assembly: Microsoft.Xrm.Sdk (in Microsoft.Xrm.Sdk.dll)

Syntax

'Declaration
<DataMemberAttribute(Order:=50)> _
Public Property NoLock As Boolean

[DataMemberAttribute(Order=50)] 
public bool NoLock { get; set; }

Property Value

Type: Boolean
true if there are no shared locks are issued against the data that would prohibit other transactions from modifying the data in the records returned from the query; otherwise, false.

Remarks

The benefit of setting NoLock to true is that it allows you to keep the system from issuing locks against the entities in your queries; this increases concurrency and performance because the database engine does not have to maintain the shared locks involved. The downside is that, because no locks are issued against the records being read, some "dirty” or uncommitted data could potentially be read. A "dirty" read is one in which the data being read is involved in a transaction from another connection. If that transaction rolls back its work, the data read from the query using NoLock will have read uncommitted data. This type of read makes processing inconsistent and can lead to problems.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Development Platforms

Windows Server 2008, Windows Server 2012, Windows 7 (All Versions), Windows 8 (All Versions)

Target Platforms

Windows Server 2008, ,Windows Server 2012, ,Windows 7 (All Versions),

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