title | description | author | ms.author | ms.reviewer | ms.date | ms.service | ms.subservice | ms.topic | dev_langs | monikerRange | |
---|---|---|---|---|---|---|---|---|---|---|---|
sys.dm_pdw_exec_requests (Transact-SQL) |
sys.dm_pdw_exec_requests holds information about all requests currently or recently active in Azure Synapse Analytics dedicated SQL pools and Analytics Platform System (PDW). |
jacinda-eng |
jacindaeng |
wiassaf, randolphwest |
12/16/2024 |
sql |
data-warehouse |
reference |
|
>=aps-pdw-2016||=azure-sqldw-latest |
[!INCLUDE applies-to-version/asa-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
[!INCLUDE synapse-analytics-od-unsupported-syntax] 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 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. |
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. |
Requires VIEW DATABASE STATE
permission.
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.