Question about joint analysis in Hail (hl.MatrixTable.union_cols)

In your documentation on logistic regression
you point to a very interesting article: (thanks for this by the way)

Given my cohorts, the best recommendation is a joint analysis using Firth test. The appropriate Hail function to join the datasets seems to be hl.MatrixTable.union_cols , is that right?

What happens when variants have an identical location in both sets to join, but have a different rsid?

union_cols uses the MatrixTable row key to join. If both are keyed by locus and alleles, then that is the join key – the rsid from the right side will be ignored.

At some point we’ll add a full set of MatrixTable join methods, which will let you join the row fields as well.

Perfect, thank you.