Following upgrade of the Spotlight Diagnostic Server, the Spotlight Statistics Repository is automatically upgraded the next time it is accessed by the Spotlight Diagnostic Server. This may be some time following the upgrade of the Spotlight Diagnostic Server, depending on how often the Spotlight Statistics Repository is accessed.
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For details of the alarm, see Spotlight Today.

If in your environment the Spotlight Statistics Repository is replicated as per a Microsoft Replication database the upgrade can fail if schema changes are required that can only be made when replication is turned off. To successfully upgrade the Spotlight Statistics Repository, the steps are to: turn replication off, upgrade the Spotlight Diagnostic Server, then re-enable replication.