When SQL Server frees up its own memory! In order to provide it to other programs?
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To say this, we'll start by talking about the target server memory,total server memory in SQL Server two registers.
Total server memory refers to how much RAM is currently occupied by SQL Server,
Target server memory is how much RAM SQL Server wants to use,
When total < target SQL Server requests memory for itself, it will not stop until the two values are very close.
If Windows wants to tell SQL Server to release a little memory, Windows adjusts the size of the target Server memory so that target<total;
SQL Server knows that you can not only request space but also release a portion of it.
Conventions on SQL Server and Windows memory usage