Sleeping/Awaiting Command Session - SQL Server

In SQL Server, a sleeping or awaiting command session is a database connection that is currently connected to the server but is not actively executing any commands. This state can occur for various reasons, such as:

When a user connects to the database, a session is created even if the user is not performing any actions. This session will remain open until the user disconnects, and it will be in the sleeping state.

When a user executes a command that takes some time to complete, the session will remain in the awaiting command state until the command finishes executing.

When a user uses connection pooling, the session may remain open even when the user disconnects, and it will be in the sleeping state until a new connection is made.

When a session is in a sleeping or awaiting command state, it is still connected to the database and holding resources. These resources can include locks on tables or memory, depending on what the session was doing before entering the sleeping state.

While sleeping sessions do not actively execute any commands, they can still impact the performance of the database server. For example, if too many sleeping sessions accumulate, it can lead to resource contention and a reduction in server performance. Additionally, some operations, such as database backups, may require exclusive access to certain resources, and sleeping sessions can prevent those resources from being released.

To manage sleeping sessions, SQL Server provides various tools such as the Activity Monitor, SQL Server Profiler, and Dynamic Management Views (DMVs). These tools can be used to identify and monitor sleeping sessions and to determine which resources are being held by those sessions. This information can then be used to troubleshoot performance issues and optimize the database server.

Sleeping or awaiting command sessions in SQL Server refer to a state where a database connection is still active but not currently executing any commands. While these sessions can be useful in some cases, they can also impact server performance and should be monitored and managed to ensure optimal performance.

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