Muokkaa

Jaa

sys.dm_pdw_exec_requests (Transact-SQL)

  • Artikkeli

Applies to: Azure Synapse Analytics Analytics Platform System (PDW)

Holds information about all requests currently or recently active in Azure Synapse Analytics dedicated SQL pools and Analytics Platform System (PDW). It lists one row per request/query.

Note

This syntax is not supported by serverless SQL pool in Azure Synapse Analytics. For serverless SQL pool, use sys.dm_exec_requests.

Column name Data type Description Range
request_id nvarchar(32) Key for this view. Unique numeric ID associated with the request. Unique across all requests in the system.
session_id nvarchar(32) Unique numeric ID associated with the session in which this query was run. See sys.dm_pdw_exec_sessions.
status nvarchar(32) Current status of the request. Running, Suspended, Completed, Cancelled, Failed.
submit_time datetime Time at which the request was submitted for execution. Valid datetime smaller or equal to the current time and start_time.
start_time datetime Time at which the request execution was started. NULL for queued requests; otherwise, valid datetime smaller or equal to current time.
end_compile_time datetime Time at which the engine completed compiling the request. NULL for requests that haven't been compiled yet; otherwise a valid datetime less than start_time and less than or equal to the current time.
end_time datetime Time at which the request execution completed, failed, or was canceled. NULL for queued or active requests; otherwise, a valid datetime smaller or equal to current time.
total_elapsed_time int Time elapsed in execution since the request was started, in milliseconds. Between 0 and the difference between submit_time and end_time.

If total_elapsed_time exceeds the maximum value for an integer, total_elapsed_time continues to be the maximum value. This condition generates the warning "The maximum value has been exceeded."
The maximum value in milliseconds is the same as 24.8 days.
label nvarchar(255) Optional label string associated with some SELECT query statements. Any string containing a-z, A-Z,0-9,_.
error_id nvarchar(36) Unique ID of the error associated with this step, if any. NULL if no error occurred. The request_id can be matched with the request_id in sys.dm_pdw_errors to view all of the listed errors for that specific request_id.
database_id int Identifier of database used by explicit context (for example, USE DB_X). See database_id in sys.databases.
command nvarchar(4000) Holds the full text of the request as submitted by the user. Any valid query or request text. Queries that are longer than 4,000 bytes are truncated.
resource_class nvarchar(20) The workload group used for this request. Static Resource Classes
staticrc10
staticrc20
staticrc30
staticrc40
staticrc50
staticrc60
staticrc70
staticrc80

Dynamic Resource Classes
SmallRC
MediumRC
LargeRC
XLargeRC
importance nvarchar(128) The Importance setting the request executed at. This is the relative importance of a request in this workload group and across workload groups for shared resources. Importance specified in the classifier overrides the workload group importance setting.

Applies to: Azure Synapse Analytics		 NULL
low
below_normal
normal (default)
above_normal
high
group_name sysname For requests utilizing resources, group_name is the name of the workload group the request is running under. If the request doesn't utilize resources, group_name is NULL.

Applies to: Azure Synapse Analytics
classifier_name sysname For requests utilizing resources, The name of the classifier used for assigning resources and importance.
resource_allocation_percentage decimal(5,2) The percentage amount of resources allocated to the request.

Applies to: Azure Synapse Analytics
result_cache_hit int Details whether a completed query used result set cache.

Applies to: Azure Synapse Analytics		 1 = Result set cache hit
0 = Result set cache miss
NULL = Query wasn't a SELECT query.
Negative integer values = Reasons why result set caching wasn't used. See remarks section for details.
client_correlation_id nvarchar(255) Optional user-defined name for a client session. To set for a session, call sp_set_session_context 'client_correlation_id', <CorrelationIDName>. You can retrieve its value with SELECT SESSION_CONTEXT (N'client_correlation_id'). For more information, see sp_set_session_context.
command2 nvarchar(max) Holds the full text of the request as submitted by the user. Holds queries that are longer than 4,000 characters. Any valid query or request text. NULL = Queries that are 4000 characters long or less. For these queries the full text can be found under the command column.

Remarks

For information about the maximum rows retained by this view, see the Metadata section in the Capacity limits article.

The negative integer value in the result_cache_hit column is a bitmap value of all applied reasons why a query's result set can't be cached. This column can be the | (Bitwise OR) product of one or more of following values. For example, -36 could be a bitwise OR of two reasons: -0x04 (-4) and -0x20 (-32).

Value Value in decimal Description
1 1 Result set cache hit
0x00 0 Result set cache miss
-0x01 -1 Result set caching is disabled on the database.
-0x02 -2 Result set caching is disabled on the session.
-0x04 -4 Result set caching is disabled due to no data sources for the query.
-0x08 -8 Result set caching is disabled due to row level security predicates.
-0x10 -16 Result set caching is disabled due to the use of system table, temporary table, or external table in the query.
-0x20 -32 Result set caching is disabled because the query contains runtime constants, user-defined functions, or nondeterministic functions.
-0x40 -64 Result set caching is disabled due to estimated result set size is greater than 10 GB.
-0x80 -128 Result set caching is disabled because the result set contains rows with large size (greater than 64 KB).
-0x100 -256 Result set caching is disabled because of the use of granular dynamic data masking.

Permissions

Requires VIEW DATABASE STATE permission.

Security

sys.dm_pdw_exec_requests doesn't filter query results according to database-specific permissions. Logins with VIEW DATABASE STATE permission can obtain results query results for all databases.

Warning

An attacker can use sys.dm_pdw_exec_requests to retrieve information about specific database objects by simply having VIEW DATABASE STATE permission and by not having database-specific permission.

Related content