Ownership Data Skew
Ownership data skew is when a single user owns more than 10,000 records of an object. This situation commonly occurs when concentrating ownership of data so that a single user or queue, or all the members of a single role or public group, owns most or all records for a particular object.
For example, a customer can assign all unassigned leads to a dummy user. This practice can seem like a convenient way to park unused data. However, it can cause performance issues if those users are moved around the hierarchy, or moved in to or out of a role or group that is the source group for a sharing rule. In both cases, Salesforce must adjust a very large number of entries in the sharing tables, which can lead to a long-running recalculation of access rights.
Distributing ownership of records across a greater number of users decreases the chance of long-running updates occurring.
If you do have a compelling reason for assigning ownership to a small number of users, you can minimize possible performance impacts by not assigning the users to a role.
If the users must have a role to share data, we recommend that you:
- Place them in a separate role at the top of the hierarchy. (Note that this user inherits access to all data owned by or shared with users below them in the hierarchy).
- Don't move them out of that top-level role to avoid triggering sharing recalculations.
- Keep them out of public groups that can be used as the source for sharing rules.