Users with the ADMIN role can index metadata to make documents and topics searchable using their corresponding facet values.
Indexing metadata is not necessary to filter on it. It may actually cause a query to return too many documents and clutter the search results.
Indexing metadata can be especially useful if a metadata key has a very large number of values. When metadata is indexed, users can type the name of the metadata value in the search box on the Homepage or Search page instead of searching for a value in a long list of filters.