Wait Type PREEMPTIVE_OS_LOOKUPACCOUNTSID

The wait type PREEMPTIVE_OS_LOOKUPACCOUNTSID is ranked #30 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 PREEMPTIVE_OS_LOOKUPACCOUNTSID wait type indicates that a request was made to look up the security identifier (SID) for a user account in the operating system. This wait type can occur when SQL Server needs to access user account information in order to verify the users credentials, check their permissions, or perform other security-related tasks. The PREEMPTIVE_OS_LOOKUPACCOUNTSID wait type can be a sign that SQL Server is spending a significant amount of time performing security-related operations, which can impact performance. It can also indicate that there are a large number of user accounts that need to be looked up, which can cause delays in processing requests.

As a database administrator or developer, you may have noticed the PREEMPTIVE_OS_LOOKUPACCOUNTSID wait type in the performance logs of your SQL Server instance. But what does this wait type mean, and why is it important to understand?

The PREEMPTIVE_OS_LOOKUPACCOUNTSID wait type indicates that SQL Server is spending time looking up the security identifier (SID) for a user account in the operating system. This is a necessary step in many security-related operations, such as verifying a users credentials or checking their permissions.

When a request is made to look up a users SID, SQL Server must wait for the operating system to provide the necessary information. This can cause delays in processing requests, and can potentially impact the overall performance of the server. If the PREEMPTIVE_OS_LOOKUPACCOUNTSID wait type is occurring frequently or for a significant amount of time, it may be a sign that SQL Server is spending too much time on security-related tasks.

One way to address this issue is to ensure that the necessary user account information is readily available to SQL Server. For example, you can use the sp_grantlogin and sp_grantdbaccess system stored procedures to grant login access and database access to users, respectively. This can help reduce the number of SID lookup requests that SQL Server needs to make, and can improve performance as a result.

Another approach is to optimize the queries and operations that are making SID lookup requests. For instance, if a query is performing a large number of security checks, it may be more efficient to use a single statement that checks for multiple permissions at once, rather than making multiple individual checks. This can reduce the number of SID lookup requests that are made, and can improve the performance of the query.

In conclusion, the PREEMPTIVE_OS_LOOKUPACCOUNTSID wait type is an important indicator of SQL Servers performance and security-related activities. By understanding this wait type and taking steps to address any issues that it may indicate, you can help ensure that your SQL Server instance is running efficiently and securely.

Wait Type PREEMPTIVE_OS_LOOKUPACCOUNTSID

Applies to

Related Waits

See Also