When Batch Mode on Rowstore Hurts Performance

Erik Darling walks us through a scenario where batch mode on rowstore can make performance of a query worse:

I’m not mad at 2019 or Batch Mode On Rowstore (BMOR) or anything.

But if I’m gonna get into it, I’m gonna document issues I run into so that hopefully they help you out, too.

One thing I ran into recently was where BMOR kicked in for a query and made it slow down.

Click through for the scenario, why it’s slower when using batch mode, and two ways you can improve the query.