Stack overflow error when deleting structured column without expanding it first

[manutremo]

I'm merging two tables using Left anti join as part of the processing of a dataflow. The purpose of this merge is just deleting some rows in the main table based on the content of the other table. This works perfect, and as a result I get a structured column as expected. However with Left anti the resulting structured column just contains nulls, so I just delete it as the following step. This works fine in the power query interface, but fails with a memory error or a stack overflow error during refresh.

It, however, works fine if I first expand the table and then delete the resulting column. So there seems to be an issue with deleting a structured column without expanding it first, which would look like a possible bug.

Has someone experienced the same?

[edhans · Accepted solution]

There are several oddities with deleting a column created from a nested join. It also breaks folding.

Rather than an anti-join, consider using a simple filter that uses List.Contains() - or in your case - not List.Contains(). This article will walk you through the equivalent of an inner join without creating unnecessary columns. By putting "not" in front of List.Contains, it will become an anti-join.

Using List.Contains To Filter Dimension Tables — ehansalytics