Hugo Kornelis

Information & Communications Technology

SQL Server Azure SQL Azure SQL Database Azure SQL DB SQL SQL Server DBA performance tuning Indexing

Zeewolde, Flevoland, Netherlands

Five stages of grief - internals of a hash spill

You know the Hash Match operator. You know it requires a lot of memory. And you also know that it sometimes needs more memory than it has, in which case it spills to tempdb and is slow.
But do you know EXACTLY what happens under the cover in the case of a hash spill? Or does you knowledge stop at "it gets slow"?
Unless you work for Microsoft on the SQL Server engineering team, there really is no need to know the internals of a hash spill. But that doesn't mean you can't be curious! Would you like to waste some time to learn about dynamic role reversal, grace hash join, bail-out, bit-vector filtering, and more, then join this sessions!

Hugo Kornelis

I make SQL Server fast (.com)

Hugo Kornelis is an established SQL Server communiity expert who spends a lot of time at various conferences. He is also a blogger, technical editor of a variety of books, and Pluralsight author. He was awarded SQL Server MVP and Data Platform MVP 12 times (2006 - 2016 / 2019 - now).

When not working for the community, he is busy at his day job: freelance database developer/consultant.

Hugo has over 20 years of SQL Server experience in various roles. He has a strong database design background, but also loves to write and tune complex queries.

Hugo's full speaker profile