> Fear column addition no more<p>This section was really surprising to read! I use the strong_migrations [1] gem to catch "NOT NULL column with a default value", because it's such a common mistake.<p>I guess I had assumed that this was just something we had to accept, based on decades of architecture decisions, and the way that Postgres was written. It never occurred to me that it was actually possible to change the default behavior of Postgres and fix the underlying issue.<p>[1] <a href="https://github.com/ankane/strong_migrations#adding-a-column-with-a-default-value" rel="nofollow">https://github.com/ankane/strong_migrations#adding-a-column-...</a>