Re : Why does databasechangelog not have a primary key?

and there are some databases that have max key sizes larger than the author + id + filename values can be. 

Wow. Really? Those only add up to a maximum of 765 characters.
I didn't think there were any modern DBMS that can't index that.

Originally there was a PK

Ah! I thought I saw PKs with earlier versions. But I wasn't sure.

Thanks for the insight.