History time. Shortly after I started using PostgreSQL, I had a need to track changes in tables. Back then - this was the early version 7.x days - there was no such option available. I set out to write a tool for it. The logical choice to do that was to pick triggers to implement this. Today the world is different, PostgreSQL gained replication, and along with this, one can hook tools into the replication and stream all the changes. Back then there was no replication.