Learn T-SQL Querying

Spill To TempDb

Spill To TempDb* happens when the available query memory (known as the memory grant) is not enough to run the required operation in memory, and rather than halting execution, the operation runs with the support of TempDB workfiles or worktables, depending on the type of spill. By resorting to I/O rather than being executed solely in memory, spills usually must be remediated as they can severely slow down query performance. We covered the common Sort and Hash spills, as follows, in the Query plan operators of interest section:

• Sort Spill*
• Hash Spill*
• Exchange Spill*