Limit how much memory sql uses

This does not require restarting your SQL Server instance, but it will cause execution plans to recompile. Just replace below with the number of megabytes you want to use:. If you have to consider any of the listed items, memory settings become more complicated.

After this change, your server should be less vulnerable to paging to disk. If the system was already paging, then you should see increased performance. Anyway, keep up the great work! Your effort and supports from others on making this tool is really appreciated. Learn more. Ask Question. Asked 9 years, 6 months ago. Active 3 years, 8 months ago. Viewed 54k times. How do I change the settings to limit the amount of RAM it can use? Improve this question.

FlavorScape FlavorScape 4 4 gold badges 10 10 silver badges 19 19 bronze badges. It often has a performance impact on anything else running on the system. If it ain't broke, you can't fix it.

This is most commonly done by people who like to see lots of free memory to make themselves feel good, but actually, any memory that's free is also unused -- that is, wasted. It actually was broke, as it would grind the server to a halt SQL Server will not immediately allocate the amount of memory specified in min server memory on startup. However, after memory usage has reached this value due to client load, SQL Server cannot free memory unless the value of min server memory is reduced.

SQL Server is not guaranteed to allocate the amount of memory specified in min server memory. If the load on the server never requires allocating the amount of memory specified in min server memory , SQL Server will run with less memory. To set max server memory configuration, monitor overall consumption of the SQL Server process in order to determine memory requirements.

Use the two server memory options, min server memory and max server memory , to reconfigure the amount of memory in megabytes managed by the SQL Server Memory Manager for an instance of SQL Server.

Under Server Memory Options , enter the amount that you want for Minimum server memory and Maximum server memory. Use the default settings to allow SQL Server to change its memory requirements dynamically based on available system resources. It is recommended to set a max server memory as detailed above. This Windows policy determines which accounts can use a process to keep data in physical memory, preventing the system from paging the data to virtual memory on disk.

Locking pages in memory may keep the server responsive when paging memory to disk occurs. Setting this option does not affect SQL Server dynamic memory management , allowing it to expand or shrink at the request of other memory clerks. When using the Lock Pages in Memory user right it is recommended to set an upper limit for max server memory as detailed above.

Setting this option should only be used when necessary, namely if there are signs that sqlservr process is being paged out. In this case, error will be reported in the Errorlog, resembling the below example: A significant part of sql server process memory has been paged out. This may result in a performance degradation. Duration: seconds. Starting with SQL Server On the Start menu, click Run. If your server is a dedicated database server there is no problem regarding memory allocation, however sometimes there are many applications running on the database server.

Moreover, some applications use memory available at their starting time and may be unable to request additional memory from Windows, if needed. In this case, to permit the other applications to work properly, we can limit SQL Server's access to memory by setting the "max server memory" option. We can change this setting to a lower value, according to our requirements. Also, there are no other resources consuming memory on our server.

By running Task Manager we can monitor memory usage in the Performance tab to get a sense of the memory usage prior to starting SQL Server:. Now let's do some activity in our instance. Let's select all rows from this table:. Now we will set the "max server memory" option to limit the memory usage by SQL Server. We can do this by right-clicking on our instance and choosing "Properties":. We can see above that "Maximum server memory" is set to MB.

This is the default value. We will change it to MB and click "OK":. The reason is that our query returns currently used memory, however max server memory controls memory used by the buffer pool, compiled memory, all cache and so on, but it does not control memory for linked server providers other than SQL Server, memory allocated by a non SQL Server DLL, memory for thread stacks, memory heaps, etc.

Microsoft recommends to allow SQL Server to use memory dynamically, however in some situations it is preferable to limit the memory usage by SQL Server.