Yvonne Vanslageren explains a solid feature in SQL Server 2019:
When SQL Server runs a query, it needs memory for operations like sorting and joining data. It also relies on memory during query compilation to hold intermediate plans while the Query Optimizer finds the best execution strategy. In parallel processing scenarios, the memory requirement grows even further.
SQL Server manages this by pre-allocating memory for each query through the SQL Server Operating System (SQLOS). This process ensures that no single query can monopolize the server’s memory.
Read on to learn more about memory grants, problems you can run into with memory grants, and one way SQL Server 2019 has improved to reduce the risk of bad memory grant estimates.