A Windows service that can optionally be installed with SQL Server. This service, which is also called MSSearch service, allows indexing selected columns in a way that allows users to search any word, phrase, or derivative of any word contained in that column.
When a record is deleted from a table, to improve concurrency SQL Server does not physically remove the row from index Leaf levels. Instead, the record is marked as deleted (ghosted). At a later point, a housekeeping process asynchronously removes the ghosted records from the Leaf level. Until the records are removed, SQL Server must skip the ghosted records during Leaf level scans.