FetchXML is a proprietary query language initially introduced in Dynamics CRM 3.0 and improved through the following versions. All the dynamics CRM views are created with this query language and we can now write reports in CRM 2011 using this query language as well.
The addition of this type of data source allows Dynamics CRM online to create reports where this is the only type of data source supported for CRM Online.
The FetchXML queries have a limitation of 5000 records per page, so you need to have this in mind when working with them. If you are in CRM on-premise, you can tune this value by touching the registry, setting a value (
1) of the
TurnOffFetchThrottling DWORD key under
HKLM\Software\Microsoft\MSCRM. For more information, ...