sys.dm_fts_index_keywords (Transact-SQL)
Returns information about the content of a full-text index for the specified table.
sys.dm_fts_index_keywords is a dynamic management function.
[!UWAGA]
To view lower-level full-text index information, use the sys.dm_fts_index_keywords_by_document dynamic management function at the document level.
Składnia
sys.dm_fts_index_keywords( DB_ID('database_name'), OBJECT_ID('table_name') )
Arguments
db_id('database_name')
A call to the DB_ID() function. This function accepts a database name and returns the database ID, which sys.dm_fts_index_keywords uses to find the specified database. If database_name is omitted, the current database ID is returned.object_id('table_name')
A call to the OBJECT_ID() function. This function accepts a table name and returns the table ID of the table containing the full-text index to inspect.
Table Returned
Column name |
Data type |
Description |
|---|---|---|
keyword |
nvarchar(4000) |
The hexadecimal representation of the keyword stored inside the full-text index.
|
display_term |
nvarchar(4000) |
The human-readable format of the keyword. This format is derived from the hexadecimal format.
|
column_id |
int |
ID of the column from which the current keyword was full-text indexed. |
document_count |
int |
Number of documents or rows containing the current term. |
Uwagi
The information returned by sys.dm_fts_index_keywords is useful for finding out the following, among other things:
Whether a keyword is part of the full-text index.
How many documents or rows contain a given keyword.
The most common keyword in the full-text index:
document_count of each keyword_value compared to the total document_count, the document count of 0xFF.
Typically, common keywords are likely to be appropriate to declare as stopwords.
[!UWAGA]
The document_count returned by sys.dm_fts_index_keywords may be less accurate for a specific document than the count returned by sys.dm_fts_index_keywords_by_document or a CONTAINS query. This potential inaccuracy is estimated to be less than 1%. This inaccuracy can occur because a document_id may be counted twice when it continues across more than one row in the index fragment, or when it appears more than once in the same row. To obtain a more accurate count for a specific document, use sys.dm_fts_index_keywords_by_document or a CONTAINS query.
Permissions
Requires membership in the sysadmin fixed server role.
Examples
A. Displaying high-level full-text index content
The following example displays information about the high-level content of the full-text index in the HumanResources.JobCandidate table of the AdventureWorks sample database. .
SELECT * FROM sys.dm_fts_index_keywords(db_id('AdventureWorks'), object_id('HumanResources.JobCandidate'))
GO
Zobacz także
Odwołanie
Full-Text Search and Semantic Search Dynamic Management Views and Functions (Transact-SQL)
sys.dm_fts_index_keywords_by_document (Transact-SQL)