sys.dm_exec_query_statistics_xml (Transact-SQL)

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

Returns query execution plan for in-flight requests. Use this DMV to retrieve showplan XML with transient statistics.

Syntax

sys.dm_exec_query_statistics_xml(session_id)

Arguments

session_id

The session ID executing the batch to be looked up. session_id is smallint. session_id can be obtained from the following dynamic management objects:

• sys.dm_exec_requests
• sys.dm_exec_sessions
• sys.dm_exec_connections

Table returned

Column Name	Data Type	Description
session_id	smallint	ID of the session. Not nullable.
request_id	int	ID of the request. Not nullable.
sql_handle	varbinary(64)	A token that uniquely identifies the batch or stored procedure that the query is part of. Nullable.
plan_handle	varbinary(64)	A token that uniquely identifies a query execution plan for a batch that is currently executing. Nullable.
query_plan	xml	Contains the runtime Showplan representation of the query execution plan that is specified with plan_handle containing partial statistics. The Showplan is in XML format. One plan is generated for each batch that contains, for example ad hoc Transact-SQL statements, stored procedure calls, and user-defined function calls. Nullable.

Limitations

Owing to a possible random access violation (AV) while executing a monitoring stored procedure with the sys.dm_exec_query_statistics_xml DMV, the Showplan XML attribute <ParameterList> value ParameterRuntimeValue was removed in SQL Server 2017 (14.x) CU 26 and SQL Server 2019 (15.x) CU 12. This value could be useful while troubleshooting long running stored procedures. You can re-enable this value in SQL Server 2017 (14.x) CU 31, SQL Server 2019 (15.x) CU 19, and later versions, using Trace Flag 2446. This trace flag enables the collection of the runtime parameter value at the cost of introducing extra overhead.

Caution

Trace Flag 2446 isn't meant to be enabled continuously in a production environment, but only for time-limited troubleshooting purposes. Using this trace flag introduces extra and possibly significant CPU and memory overhead, as it creates a Showplan XML fragment with runtime parameter information, whether the sys.dm_exec_query_statistics_xml DMV is called or not.

In SQL Server 2022 (16.x), Azure SQL Database, and Azure SQL Managed Instance, you can accomplish the same functionality at the database level using the FORCE_SHOWPLAN_RUNTIME_PARAMETER_COLLECTION option in ALTER DATABASE SCOPED CONFIGURATION (Transact-SQL).

Remarks

This system function is available starting with SQL Server 2016 (13.x) with Service Pack 1. For more information, see KB 3190871.

This system function works under both standard and lightweight query execution statistics profiling infrastructure. For more information, see Query Profiling Infrastructure.

Under the following conditions, no Showplan output is returned in the query_plan column of the returned table for sys.dm_exec_query_statistics_xml:

• If the query plan that corresponds to the specified session_id is no longer executing, the query_plan column of the returned table is null. For example, this condition might occur if there's a time delay between when the plan handle was captured and when it was used with sys.dm_exec_query_statistics_xml

Due to a limitation in the number of nested levels allowed in the xml data type, sys.dm_exec_query_statistics_xml can't return query plans that meet or exceed 128 levels of nested elements. In earlier versions of SQL Server, this condition prevented the query plan from returning and generates error 6335. In SQL Server 2005 (9.x) Service Pack 2 and later versions, the query_plan column returns NULL.

Permissions

Requires VIEW SERVER STATE permission on the server, in SQL Server 2019 (15.x) and earlier versions.

Requires VIEW SERVER PERFORMANCE STATE permission on the server, in SQL Server 2022 (16.x) and later versions.

Requires the VIEW DATABASE STATE permission in the database, on SQL Database Premium Tiers.

Requires the Server admin or a Microsoft Entra admin account on SQL Database Standard and Basic Tiers.

Examples

A. Look at live query plan and execution statistics for a running batch

The following example queries sys.dm_exec_requests to find the interesting query and copy its session_id from the output.

SELECT *
FROM sys.dm_exec_requests;
GO

Then, to obtain the live query plan and execution statistics, use the copied session_id with system function sys.dm_exec_query_statistics_xml. Run this query in a different session than the session in which your query is running.

SELECT * FROM sys.dm_exec_query_statistics_xml(< copied session_id >);
GO

Or, combined for all running requests. Run this query in a different session than the session in which your query is running.

SELECT eqs.query_plan,
       er.session_id,
       er.request_id,
       er.database_id,
       er.start_time,
       er.[status],
       er.wait_type,
       er.wait_resource,
       er.last_wait_type,
       (er.cpu_time / 1000) AS cpu_time_sec,
       (er.total_elapsed_time / 1000) / 60 AS elapsed_time_minutes,
       (er.logical_reads * 8) / 1024 AS logical_reads_KB,
       er.granted_query_memory,
       er.dop,
       er.row_count,
       er.query_hash,
       er.query_plan_hash
FROM sys.dm_exec_requests AS er
CROSS APPLY sys.dm_exec_query_statistics_xml(session_id) AS eqs
WHERE er.session_id <> @@SPID;
GO

Related content

• DBCC TRACEON - Trace Flags (Transact-SQL)
• System dynamic management views
• Database related dynamic management views (Transact-SQL)