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sys.dm_exec_function_stats (Transact-SQL)

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Applies to: SQL Server 2016 (13.x) and later Azure SQL Database Azure SQL Managed Instance

Returns aggregate performance statistics for cached functions. The view returns one row for each cached function plan, and the lifetime of the row is as long as the function remains cached. When a function is removed from the cache, the corresponding row is eliminated from this view. At that time, a Performance Statistics SQL trace event is raised similar to sys.dm_exec_query_stats. Returns information about scalar functions, including in-memory functions and CLR scalar functions. Does not return information about table valued functions, and about scalar functions that are inlined with Scalar UDF Inlining.

In Azure SQL Database, dynamic management views cannot expose information that would impact database containment or expose information about other databases the user has access to. To avoid exposing this information, every row that contains data that doesn't belong to the connected tenant is filtered out.

Note

The results of sys.dm_exec_function_stats may vary with each execution as the data only reflects finished queries, and not ones still in-flight.

Column name Data type Description
database_id int Database ID in which the function resides.

In Azure SQL Database, the values are unique within a single database or an elastic pool, but not within a logical server.
object_id int Object identification number of the function.
type char(2) Type of the object: FN = Scalar valued functions
type_desc nvarchar(60) Description of the object type: SQL_SCALAR_FUNCTION
sql_handle varbinary(64) This can be used to correlate with queries in sys.dm_exec_query_stats that were executed from within this function.
plan_handle varbinary(64) Identifier for the in-memory plan. This identifier is transient and remains constant only while the plan remains in the cache. This value may be used with the sys.dm_exec_cached_plans dynamic management view.

Will always be 0x000 when a natively compiled function queries a memory-optimized table.
cached_time datetime Time at which the function was added to the cache.
last_execution_time datetime Last time at which the function was executed.
execution_count bigint Number of times that the function has been executed since it was last compiled.
total_worker_time bigint Total amount of CPU time, in microseconds, that was consumed by executions of this function since it was compiled.

For natively compiled functions, total_worker_time may not be accurate if many executions take less than 1 millisecond.
last_worker_time bigint CPU time, in microseconds, that was consumed the last time the function was executed. 1
min_worker_time bigint Minimum CPU time, in microseconds, that this function has ever consumed during a single execution. 1
max_worker_time bigint Maximum CPU time, in microseconds, that this function has ever consumed during a single execution. 1
total_physical_reads bigint Total number of physical reads performed by executions of this function since it was compiled.

Will always be 0 querying a memory-optimized table.
last_physical_reads bigint Number of physical reads performed the last time the function was executed.

Will always be 0 querying a memory-optimized table.
min_physical_reads bigint Minimum number of physical reads that this function has ever performed during a single execution.

Will always be 0 querying a memory-optimized table.
max_physical_reads bigint Maximum number of physical reads that this function has ever performed during a single execution.

Will always be 0 querying a memory-optimized table.
total_logical_writes bigint Total number of logical writes performed by executions of this function since it was compiled.

Will always be 0 querying a memory-optimized table.
last_logical_writes bigint Number of the number of buffer pool pages dirtied the last time the plan was executed. If a page is already dirty (modified) no writes are counted.

Will always be 0 querying a memory-optimized table.
min_logical_writes bigint Minimum number of logical writes that this function has ever performed during a single execution.

Will always be 0 querying a memory-optimized table.
max_logical_writes bigint Maximum number of logical writes that this function has ever performed during a single execution.

Will always be 0 querying a memory-optimized table.
total_logical_reads bigint Total number of logical reads performed by executions of this function since it was compiled.

Will always be 0 querying a memory-optimized table.
last_logical_reads bigint Number of logical reads performed the last time the function was executed.

Will always be 0 querying a memory-optimized table.
min_logical_reads bigint Minimum number of logical reads that this function has ever performed during a single execution.

Will always be 0 querying a memory-optimized table.
max_logical_reads bigint Maximum number of logical reads that this function has ever performed during a single execution.

Will always be 0 querying a memory-optimized table.
total_elapsed_time bigint Total elapsed time, in microseconds, for completed executions of this function.
last_elapsed_time bigint Elapsed time, in microseconds, for the most recently completed execution of this function.
min_elapsed_time bigint Minimum elapsed time, in microseconds, for any completed execution of this function.
max_elapsed_time bigint Maximum elapsed time, in microseconds, for any completed execution of this function.
total_page_server_reads bigint Total number of page server reads performed by executions of this function since it was compiled.

Applies To: Azure SQL Database Hyperscale.
last_page_server_reads bigint Number of page server reads performed the last time the function was executed.

Applies To: Azure SQL Database Hyperscale.
min_page_server_reads bigint Minimum number of page server reads that this function has ever performed during a single execution.

Applies To: Azure SQL Database Hyperscale.
max_page_server_reads bigint Maximum number of page server reads that this function has ever performed during a single execution.

Applies To: Azure SQL Database Hyperscale.

Permissions

On SQL Server and SQL Managed Instance, requires VIEW SERVER STATE permission.

On SQL Database Basic, S0, and S1 service objectives, and for databases in elastic pools, the server admin account, the Microsoft Entra admin account, or membership in the ##MS_ServerStateReader## server role is required. On all other SQL Database service objectives, either the VIEW DATABASE STATE permission on the database, or membership in the ##MS_ServerStateReader## server role is required.

Permissions for SQL Server 2022 and later

Requires VIEW SERVER PERFORMANCE STATE permission on the server.

Examples

The following example returns information about the top ten functions identified by average elapsed time.

SELECT TOP 10 d.object_id, d.database_id, OBJECT_NAME(object_id, database_id) 'function name',   
    d.cached_time, d.last_execution_time, d.total_elapsed_time,  
    d.total_elapsed_time/d.execution_count AS [avg_elapsed_time],  
    d.last_elapsed_time, d.execution_count  
FROM sys.dm_exec_function_stats AS d  
ORDER BY [total_worker_time] DESC;

See Also

Execution Related Dynamic Management Views and Functions (Transact-SQL)
sys.dm_exec_sql_text (Transact-SQL)
sys.dm_exec_query_stats (Transact-SQL)

sys.dm_exec_trigger_stats (Transact-SQL)
sys.dm_exec_procedure_stats (Transact-SQL)