transform noise words Server Configuration Option
Use the transform noise words
server configuration option to suppress an error message if noise words, that is 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 | Noise words (or stopwords) are not transformed. When a full-text query contains noise words, the query returns zero rows, and SQL Server raises a warning. This is the default behavior. Note that the warning is a run-time warning. Therefore, if the full-text clause in the query is not executed, the warning is not 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 are 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)') . Notice that CONTAINS(<column_name>, 'NEAR(hello,is)') would be transformed into simply CONTAINS(<column_name>, hello) because there is 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 be 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
Example
The following example sets transform noise words
to 1
.
sp_configure 'show advanced options', 1;
RECONFIGURE;
GO
sp_configure 'transform noise words', 1;
RECONFIGURE;
GO
See Also
Server Configuration Options (SQL Server)
CONTAINS (Transact-SQL)