How to troubleshoot SQL Server error 8645

SUMMARY

This step-by-step article describes how to troubleshoot SQL Server error 8645. You may receive the error 8645 when there is a high server workload or when the servers are experiencing high memory pressure.

 

Symptoms

You may see the following 8645 error sporadically:

Error 8645: A time out occurred while waiting for memory resources to execute the query. Re-run the query.

Additionally, you may also see one or more of the following symptoms:

•	When new users try to connect to SQL Server, they receive a "login failed" error message.
•	Users are disconnected and they receive various error messages.
•	CPU usage is very high on the server.
•	When you run

 

Causes

The error message 8645 is raised when memory-intensive queries, such as those involving sorting and hashing, are queued and are unable to obtain the requested memory before a time-out period. SQL Server waits for memory for a length of time that is based on the query wait configuration value. By default, the query wait value is set to -1, which means SQL Server waits for 25 times the estimated cost of the query. If you modify the query wait value to a non-negative number, SQL Server waits for the number of seconds that you specify in the value of the query wait option.