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Server configuration: transform noise words

Applies to: SQL Server

Use the transform noise words server configuration option to suppress an error message if noise words (also known as stopwords) cause a Boolean operation on a full-text query to return zero rows. This option is useful for full-text queries that use the CONTAINS predicate in which Boolean operations or NEAR operations include noise words. The possible values are described in the following table.

Value Description
0 (default) Noise words (or stopwords) aren't transformed. When a full-text query contains noise words, the query returns zero rows, and SQL Server raises a warning.

Note: The warning is a run-time warning. Therefore, if the full-text clause in the query isn't executed, the warning isn't raised. For a local query, only one warning is raised, even when there are multiple full-text query clauses. For a remote query, the linked server might not relay the error; therefore, the warning might not be raised.
1 Noise words (or stopwords) are transformed. They're ignored, and the rest of the query is evaluated.

If noise words are specified in a proximity term, SQL Server removes them. For example, the noise word is is removed from CONTAINS(<column_name>, 'NEAR (hello,is,goodbye)'), transforming the search query into CONTAINS(<column_name>, 'NEAR(hello,goodbye)'). Note: CONTAINS(<column_name>, 'NEAR(hello,is)') would be transformed into simply CONTAINS(<column_name>, hello) because there's only one valid search term.

Effects of the transform noise words setting

This section illustrates the behavior of queries containing a noise word, the, under the alternate settings of transform noise words. The sample full-text query strings are assumed to run against a table row containing the following data: [1, "The black cat"].

Note

All such scenarios can generate a noise word warning.

  • With transform noise words set to 0:

    Query string Result
    cat AND the No results (The behavior is the same for the AND cat.)
    cat NEAR the No results (The behavior is the same for the NEAR cat.)
    the AND NOT black No results
    black AND NOT the No results

  • With transform noise words set to 1:

    Query string Result
    cat AND the Hit for row with ID 1
    cat NEAR the Hit for row with ID 1
    the AND NOT black No results
    black AND NOT the Hit for row with ID 1

Examples

The following example sets transform noise words to 1.

EXECUTE sp_configure 'show advanced options', 1;
RECONFIGURE;
GO

EXECUTE sp_configure 'transform noise words', 1;
RECONFIGURE;
GO

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