Learn T-SQL Querying

Queries with excessive memory grants

In Chapter 4, Exploring Query Execution Plans, we covered a few different topics regarding memory grants, particularly in the Query plan properties of interest section. It is important for SQL Server to get memory grants correct. If a query asks for more memory than it needs, other queries may be stuck waiting for a memory grant even though this memory is not actually being used. Similarly, if the query asks for less memory than it needs, it could end up spilling to disk, which will slow it down significantly. In the previous section, Finding resource intensive queries, we explored the different ways to sort results from sys.dm_exec_query_stats to surface queries that consume a large amount of resources. ...