The Search Update job performs the following actions on the search index: updates the index, releases expired locks on users and objects, and repairs the search index according to the Search Service Manager repair settings.

The Search Update job is located in the Intrinsic Operations administrative folder. The default frequency of the Search Update job is one hour, which is suitable for most portal deployments. If your search index is very large, the Search Update Agent might not be able to finish in one hour, so you should edit the frequency of the job.