What is physical memory in SQL Server?
Physical memory refers to a volatile hardware main memory module installed in the system (Dynamic Random Access Memory (DRAM)). Physical memory is the intermediate storage location that is used to store, preserve, and recall data. Access to physical memory is much faster than access to non-volatile disk storage.
What is Server physical memory?
Physical memory (also known as random-access memory (RAM)) is a form of very fast, but volatile data storage. This makes physical memory roughly 100,000 times faster than a common physical disk.
What happens when there is low free memory in SQL Server?
If there is low free memory for the OS, SQL Server will release memory back to the operating system until the low memory condition is alleviated, or until SQL Server reaches the min server memory limit. However, you can override the option to dynamically use memory by using the min server memory, and max server memory server configuration options.
How does SQL Server know when it needs more memory?
By default, SQL Server changes its memory requirements dynamically, on the basis of available system resources. If SQL Server needs more memory, it queries the operating system to determine whether free physical memory is available and uses the available memory.
Is there a memory limit for SQL Server?
Starting in SQL Server 2012, the 64GB memory limit for Standard Edition applies only to data cache, and other parts of SQL Server can use memory above that. Standard Edition’s data cache limit goes up to 128GB in SQL Server 2014. Read more about it here.
When is memory too low or max memory too high?
If the same value is specified for both min server memory and max server memory, then once the memory allocated to the SQL Server Database Engine reaches that value, the SQL Server Database Engine stops dynamically freeing and acquiring memory for the buffer pool.