sys.dm_exec_connections (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
SQL analytics endpoint in Microsoft Fabric
Warehouse in Microsoft Fabric
Returns information about the connections established to this instance of the database engine and the details of each connection. Returns server wide connection information for SQL Server and Azure SQL Managed Instance. Returns connection information for the current database in Azure SQL Database. Returns connection information for all databases in the same elastic pool for databases in elastic pools in Azure SQL Database.
Note
To call this from dedicated SQL pool in Azure Synapse Analytics or Analytics Platform System (PDW), see sys.dm_pdw_exec_connections (Transact-SQL). For serverless SQL pool or Microsoft Fabric use sys.dm_exec_connections.
| Column name | Data type | Description |
|---|---|---|
| session_id | int | Identifies the session associated with this connection. Is nullable. |
| most_recent_session_id | int | Represents the session ID for the most recent request associated with this connection. (SOAP connections can be reused by another session.) Is nullable. |
| connect_time | datetime | Timestamp when connection was established. Is not nullable. |
| net_transport | nvarchar(40) | When MARS is used, returns Session for each additional connection associated with a MARS logical session. Note: Describes the physical transport protocol that is used by this connection. Is not nullable. |
| protocol_type | nvarchar(40) | Specifies the protocol type of the payload. It currently distinguishes between TDS ("TSQL"), "SOAP", and "Database Mirroring". Is nullable. |
| protocol_version | int | Version of the data access protocol associated with this connection. Is nullable. |
| endpoint_id | int | An identifier that describes what type of connection it is. This endpoint_id can be used to query the sys.endpoints view. Is nullable. |
| encrypt_option | nvarchar(40) | Boolean value to describe whether encryption is enabled for this connection. Is not nullable. For HADR mirroring endpoints, this column always returns FALSE. Use the sys.database_mirroring_endpoints DMV instead to check if connections to a HADR mirroring endpoint are encrypted. |
| auth_scheme | nvarchar(40) | Specifies SQL Server/Windows Authentication scheme used with this connection. Is not nullable. |
| node_affinity | smallint | Identifies the memory node to which this connection has affinity. Is not nullable. |
| num_reads | int | Number of byte reads that have occurred over this connection. Is nullable. |
| num_writes | int | Number of byte writes that have occurred over this connection. Is nullable. |
| last_read | datetime | Timestamp when last read occurred over this connection. Is nullable. |
| last_write | datetime | Timestamp when last write occurred over this connection. Is nullable. |
| net_packet_size | int | Network packet size used for information and data transfer. Is nullable. |
| client_net_address | varchar(48) | Host address of the client connecting to this server. Is nullable. |
| client_tcp_port | int | Port number on the client computer that is associated with this connection. Is nullable. In Azure SQL Database, this column always returns NULL. |
| local_net_address | varchar(48) | Represents the IP address on the server that this connection targeted. Available only for connections using the TCP transport provider. Is nullable. In Azure SQL Database, this column always returns NULL. |
| local_tcp_port | int | Represents the server TCP port that this connection targeted if it were a connection using the TCP transport. Is nullable. In Azure SQL Database, this column always returns NULL. |
| connection_id | uniqueidentifier | Identifies each connection uniquely. Is not nullable. |
| parent_connection_id | uniqueidentifier | Identifies the primary connection that the MARS session is using. Is nullable. |
| most_recent_sql_handle | varbinary(64) | The SQL handle of the last request executed on this connection. The most_recent_sql_handle column is always in sync with the most_recent_session_id column. Is nullable. |
| pdw_node_id | int | Applies to: Azure Synapse Analytics, Analytics Platform System (PDW) The identifier for the node that this distribution is on. |
Permissions
On SQL Server and SQL Managed Instance, requires VIEW SERVER STATE permission.
On Azure 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.
Physical joins
Relationship cardinalities
| First element | Second element | Relationship |
|---|---|---|
sys.dm_exec_sessions.session_id |
sys.dm_exec_connections.session_id |
One-to-zero or one-to-many |
sys.dm_exec_requests.connection_id |
sys.dm_exec_connections.connection_id |
Many-to-one |
sys.dm_broker_connections.connection_id |
sys.dm_exec_connections.connection_id |
One-to-one |
Most commonly, for each row in sys.dm_exec_connections there is a single matching row in sys.dm_exec_sessions. However, in some cases such as system internal sessions or Service Broker activation procedures, there may be a row in sys.dm_exec_sessions without a matching row in sys.dm_exec_connections.
When MARS is used, there may be multiple rows in sys.dm_exec_connections for a row in sys.dm_exec_sessions, one row for the parent connection, and one row for each MARS logical session. The latter rows can be identified by the value in the net_transport column being set to Session. For these connections, the value in the connection_id column of sys.dm_exec_connections matches the value in the connection_id column of sys.dm_exec_requests for MARS requests in progress.
Examples
The following Transact-SQL query gathers information about a query's own connection.
SELECT
c.session_id, c.net_transport, c.encrypt_option,
c.auth_scheme, s.host_name, s.program_name,
s.client_interface_name, s.login_name, s.nt_domain,
s.nt_user_name, s.original_login_name, c.connect_time,
s.login_time
FROM sys.dm_exec_connections AS c
JOIN sys.dm_exec_sessions AS s
ON c.session_id = s.session_id
WHERE c.session_id = @@SPID;
Next steps
Learn more about related concepts in the following articles: