Professional SQL Server™ 2005 Programming

21.1. Full-Text Search Architecture

The architecture surrounding FTS is something that confuses a lot of people. When you realize how the different pieces play together to make FTS happen, the confusion isn't that surprising.

The first thing to recognize is that the core of Full-Text Search isn't really part of SQL Server at all. Actually, it is a shared technology item that originally comes from Microsoft Index Server. The technology was originally implemented through a service known as MSSearch, and is now in its own service that is controlled by the SQL Server team (same original code base by my understanding though). This new service, called SQL Server FullText Search (it will have an instance name after it in the services applet if it is not part of the default SQL Server instance), is excellent at examining raw text data and aggregating word lists. By separating SQL Server's implementation of Full-Text Search from the O/S Indexing Service, Microsoft was able to increase the efficiency of how the full-text service communicates with the core database engine. The SQL Server FullTextService — or FTS — maintains an association between the individual words and phrases and the places that the FTS has encountered them.

Figure 21.1. Figure 21-1

In order to perform full-text queries against any SQL Server table, you must build a full-text index for that table. The construction and ...