Wait Type RESOURCE_SEMAPHORE

The wait type RESOURCE_SEMAPHORE is ranked #27 by Stedman Solutions and Database Health Monitor.

Wait statistics, in the context of SQL Server, refer to the amount of time that a query spends waiting to access data in the database. When a client application requests data from the database, the request is placed in a queue and the client application must wait for its turn to access the data. The time that the query spends waiting is called a "wait" and is tracked by SQL Server. This information can be used to identify potential performance bottlenecks and optimize the performance of the database. Wait statistics are commonly used by database administrators to diagnose and troubleshoot performance issues in SQL Server.


In SQL Server, the RESOURCE_SEMAPHORE wait type indicates that a request for a resource (such as a memory grant) was blocked because the maximum amount of resources that can be granted at one time was already in use. This wait type can occur when there is a high volume of concurrent requests that require a significant amount of resources, and the server is unable to grant additional resources to those requests due to the maximum limit being reached. In other words, the RESOURCE_SEMAPHORE wait type indicates that SQL Server is experiencing a temporary bottleneck in its ability to allocate resources to requests, which can result in slower performance for those requests.

Applies to

Related Waits

RESOURCE_QUEUE
RESOURCE_SEMAPHORE_MUTEX
RESOURCE_SEMAPHORE_QUERY_COMPILE

See Also


All Wait Types