SQL Extensions in Microsoft Windows Search

Microsoft Windows Search, based on the SQL-92 and SQL-99 standards, improves full-text, document-based searches in document-management or knowledge-management applications. Windows Search improvements include the following:

128 Character Identifier Names

While SQL-92 and SQL-99 restrict column and other identifiers to 18 characters, Windows Search supports 128-character column names. See Identifiers for more information.

Accent-Insensitive Searching

In addition to searching that is not case-sensitive, Windows Search supports searching that is not sensitive to accent. See Diacritic Sensitivity in Searches for more information.

Column Weighting

Queries that search more than one column can specify the importance of each column. The CONTAINS and FREETEXT predicates both support column weighting.

NULL Predicate

Although full-text content indexing has no defined set of columns, queries can require that members of the result set do or do not have specified columns. It is not possible to differentiate between a document has a given property with the value set to NULL, and a document that does not have the property at all.

Rank Modification

You can manipulate the search results ranking by using weights on properties and on aliased groups of properties. Rank coercion supports direct manipulation of the relevance ranking based on the criteria you specify.