sys.dm_pdw_exec_requests (Transact-SQL)
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 Classesstaticrc10 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 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 SERVER STATE
permission.
Security
sys.dm_pdw_exec_requests
doesn't filter query results according to database-specific permissions. Logins with VIEW SERVER 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 SERVER STATE
permission and by not having database-specific permission.