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Breaking Changes to Full-Text Search in SQL Server 2005

This topic describes Full-Text Search changes that might require changes to applications.

Breaking Changes That Affect Applications

The following breaking changes apply to Full-Text Search in Microsoft SQL Server 2005.

Feature Description

Word breakers and filters

Word breakers and filters used by SQL Server Full-Text Search have been modified significantly to achieve improvements in functionality and reliability. In some specific cases, changes made to the word breakers have the potential to impact how some data is tokenized. This can result in tokens being created in SQL Server 2005 that are different from tokens created in SQL Server 2000. For example, in SQL Server 2005, compound word tokenizing for German has been improved, and now compounds with more than two component words can be tokenized. This could impact query results.

FULLTEXTCATALOG property

In SQL Server 2000, Itemcount returned the aggregate of the number of indexed rows in each full-text indexed table in the full-text catalog, plus one for every table in the catalog. In SQL Server 2005, this has been changed to reflect accurately the aggregate of the number of indexed rows in each full-text indexed table in the full-text catalog.

Length of full-text catalog names

In SQL Server 2005, the length of full-text catalog names is restricted to 120 characters, reduced from 128 in previous releases of SQL Server.

Microsoft Full-Text Engine for SQL Server service and third party filters

Microsoft Full-Text Engine for SQL Server (MSFTESQL) service does not load components that are not signed by Microsoft, by default.

A third party filter, such as a PDF filter, that is currently installed on the server is not loaded by the MSFTESQL service by default after upgrade.

Discontinued Full-Text Search properties

The following Full-Text Search related properties and settings have been removed from SQL Server 2005.

  • DataTimeout
  • ConnectTimeout
  • Clean_up
  • LogSize

Multiple instances of SQL Server 2005 cannot share Microsoft Full-Text Search Engine for SQL Server (MSFTESQL) service.

On upgrade to SQL Server 2005, each SQL Server instance has a dedicated instance of the Microsoft Full-Text Search Engine for SQL Server (MSFTESQL) service.

Path of Full-Text Search catalogs

In SQL Server 2005, the path in the sysfulltextcatalogs view and the path returned by the sp_help_fulltext_catalogs and sp_help_fulltext_catalogs_cursor system stored procedures has changed. In SQL Server 2000, full-text catalogs existed in the root directory. In SQL Server 2005, they are found in the FTData directory.

Full-text indexes and non-deterministic and imprecise computed columns

SQL Server 2005 does not allow you to create full-text indexes on non-deterministic and imprecise computed columns. Such columns cannot be used as type columns, or as full-text key columns.

sysfulltextnotify

The sysfulltextnotify view is undocumented in SQL Server 2000, but it could still be queried. This view has been removed in SQL Server 2005.

Full-text indexes and system databases

In SQL Server 2000, full-text indexes were supported on the master, tempdb and model databases. SQL Server 2005 does not support this. Any full-text catalogs in these databases are removed during the upgrade to SQL Server 2005.

Global word breakers and filters

In SQL Server 2000, new word breakers and filters could only be added as global operating system level components. SQL Server 2005 allows the instance-level registration of new word breakers and filters. This provides functional and security isolation between instances.

Additional space requirement for Full-Text Search

Because the document identifier (DOCID) map in SQL Server 2005 is stored in the database, the size requirement on the database side has increased. However, the size requirement on the full-text catalog side has decreased.

See Also

Concepts

Behavior Changes to Full-Text Search in SQL Server 2005

Other Resources

Full-Text Search Backward Compatibility
Full-Text Search

Help and Information

Getting SQL Server 2005 Assistance