Use the locks option to set the maximum number of available locks, thereby limiting the amount of memory Microsoft® SQL Server™ uses for locks. The default setting is 0, which allows SQL Server to allocate and deallocate locks dynamically based on changing system requirements.
When the server is started with locks set to 0, the lock manager allocates two percent of the memory allocated to SQL Server to an initial pool of lock structures. As the pool of locks is exhausted, additional locks are allocated. The dynamic lock pool does not allocate more than 40 percent of the memory allocated to SQL Server.
Generally, if more memory is required for locks than is available in current memory, and more server memory is available (the max server memory threshold has not been reached), SQL Server allocates memory dynamically to satisfy the request for locks. However, if allocating that memory would cause paging at the operating system level (for example, if another application was running on the same computer as an instance of SQL Server and using that memory), more lock space is not allocated.
Allowing SQL Server to use locks dynamically is the recommended configuration. However, you can set locks and override SQL Server’s ability to allocate lock resources dynamically. Increase this value if SQL Server displays a message that you have exceeded the number of available locks. Because each lock consumes memory (96 bytes per lock), increasing this value can require increasing the amount of memory dedicated to the server.
locks is an advanced option. If you are using the sp_configure system stored procedure to change the setting, you can change locks only when show advanced options is set to 1. The setting takes effect after stopping and restarting the server.
To set the locks option
A. List the advanced configuration options
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USE master EXEC sp_configure ‘show advanced option’, ‘1’ —Here is the message: Configuration option ‘show advanced options’ changed from 0 to 1. Run the RECONFIGURE command to install. RECONFIGURE |
B. Change a configuration option
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USE master EXEC sp_configure ‘locks’, ‘0’ RECONFIGURE WITH OVERRIDE |
