The Asyncoperation tables grow very large in Microsoft Dynamics CRM 4.0
This problem is fixed in the latest cumulative update rollup for Microsoft Dynamics CRM 4.0. For more information, click the following article number to view the article in the Microsoft Knowledge Base: 949256 (http://support.microsoft.com/kb/949256/ ) Microsoft Dynamics CRM 4.0 updates and hotfixes
To enable this hotfix, the following registry key must be added: AsyncRemoveCompletedJobs. To add the registry key, complete the following steps: Click Start, click Run, type regedit, and then click OK. Locate the following registry subkey: HKEY_LOCAL_MACHINESoftwareMicrosoftMSCRM Right-click MSCRM, point to New, and then click DWORD Value. Type AsyncRemoveCompletedJobs for the name of the key. Right-click AsyncRemoveCompletedJobs, click Modify and then type 1 in the Value data field.
When the value of this registry key is set to 1, the following asynchronous jobs will be removed immediately after completion: CollectSQMData PersistMatchCode FullTextCatalogIndex UpdateContractStates