Start a re-indexing of the database.
Currently, this method does not perform any operation. If needed, refer to re-index state in MS SQL Server change tracking and how to get triggers when it starts and completes (or errors) https://docs.microsoft.com/en-us/sql/relational-databases/search/populate-full-text-indexes.
For more information, refer to Upsert(FullTextSearchItem) and Speeding Up Forms Recognition Using the Full Text Search Feature.