Microsoft® SQL Server 2008 R2 Unleashed
by Ray Rankins, Paul Bertucci, Chris Gallelli, Alex T. Silverstein
Indexing
The indexing engine connects to your database and extracts the content from the tables you are full-text indexing. It then sends this stream to COM components called filters (or IFilters). These COM components are run in an out-of-process service called the FT Daemon Host. These filters are able to understand the content and can extract text data from them. For example, if you store XML or Word documents in your database, these filters can understand this data or binary data and emit words and/or tokens it finds in there. The filters chosen are the default text ones if you are using char, varchar, or text data types or XML if you are using the xml data type. If you are indexing varbinary documents, the indexing engine reads the document ...