If you’re making a large number of changes that affect sharing rules, including changes to sharing rules, roles, territories, or public groups, you can temporarily suspend automatic sharing rule calculations and resume them after you finish your updates. You must resume calculations and do a full sharing rule recalculation, or you can experience sharing inconsistencies in your records.
The deferred sharing calculation feature is not enabled by default. To enable this feature for your organization, please contact Salesforce Customer Support with the following information:
1. Target Org ID:
2. I understand that if group membership/sharing rule calculation is paused, changes to group membership or sharing rules will not take effect until we (the customer) resume and recalculate them. A full recalculation of groups and sharing rules will need to be performed, and depending on the size of the organization, recalculating sharing rules may take a considerable amount of time. (I understand / I will defer application)
3. I confirmed the best practices information in the following Tips Sheet. (Yes / No)
4. Please provide the reason for requesting the activation of this feature, and detailed business reasons for the specific problems or issues you expect this feature to resolve.
Understanding Defer Sharing Calculations
http://resources.docs.salesforce.com/228/18/en-us/sfdc/pdf/salesforce_defer_sharing_tipsheet.pdf
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