sys.dm_exec_sql_text

Artikkeli
12/03/2008

Returns the text of the SQL batch that is identified by the specified sql_handle. This table-valued function replaces the system function fn_get_sql.

Syntax

sys.dm_exec_sql_text(sql_handle)

Arguments

sql_handle
Is the SQL handle of the batch to be looked up. sql_handle is varbinary(64). sql_handle can be obtained from the following dynamic management objects:
- sys.dm_exec_query_stats
- sys.dm_exec_requests
- sys.dm_exec_cursors
- sys.dm_exec_xml_handles
- sys.dm_exec_query_memory_grants

Table Returned

Column name	Data type	Description
dbid	smallint	ID of database. Is NULL for ad hoc and prepared SQL statements.
objectid	int	ID of object. Is NULL for ad hoc and prepared SQL statements.
number	smallint	For a numbered stored procedure, this column returns the number of the stored procedure. For more information, see sys.numbered_procedures (Transact-SQL). Is NULL for ad hoc and prepared SQL statements.
encrypted	bit	1 = SQL text is encrypted. 0 = SQL text is not encrypted.
text	nvarchar(max)	Text of the SQL query. Is NULL for encrypted objects.

Remarks

For batches, the SQL handles are hash values based on the SQL text. For database objects such as stored procedures, triggers or functions, the SQL handles are derived from the database ID, object ID, and object number.

Permissions

Requires VIEW SERVER STATE permission on the server.

Examples

A. Obtaining information about the top five queries by average CPU time

The following example returns the text of the SQL statement and average CPU time for the top five queries.

SELECT TOP 5 total_worker_time/execution_count AS [Avg CPU Time],
    SUBSTRING(st.text, (qs.statement_start_offset/2)+1, 
        ((CASE qs.statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
         ELSE qs.statement_end_offset
         END - qs.statement_start_offset)/2) + 1) AS statement_text
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS st
ORDER BY total_worker_time/execution_count DESC;

B. Providing batch-execution statistics

The following example returns the text of SQL queries that are being executed in batches and provides statistical information about them.

SELECT s2.dbid, 
    s1.sql_handle,  
    (SELECT TOP 1 SUBSTRING(s2.text,statement_start_offset / 2+1 , 
      ( (CASE WHEN statement_end_offset = -1 
         THEN (LEN(CONVERT(nvarchar(max),s2.text)) * 2) 
         ELSE statement_end_offset END)  - statement_start_offset) / 2+1))  AS sql_statement,
    execution_count, 
    plan_generation_num, 
    last_execution_time,   
    total_worker_time, 
    last_worker_time, 
    min_worker_time, 
    max_worker_time,
    total_physical_reads, 
    last_physical_reads, 
    min_physical_reads,  
    max_physical_reads,  
    total_logical_writes, 
    last_logical_writes, 
    min_logical_writes, 
    max_logical_writes  
FROM sys.dm_exec_query_stats AS s1 
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS s2  
WHERE s2.objectid is null 
ORDER BY s1.sql_handle, s1.statement_start_offset, s1.statement_end_offset;

Change History

Release	History
12 December 2006	Changed content: Updated the description of sql_handle. Added that prepared statements will return NULL in the dbid, objectid, and number columns.
14 April 2006	Changed content: Updated the descriptions for the columns returned to include null-value definitions. Corrected the examples.
5 December 2005	Changed content: Changed data type of text field from text to nvarchar(max).

Jaa