Many people around the world admire the Uber’s article “Why Uber Engineering Switched from Postgres to MySQL”, but I think this article contains many mistakes.

So, I’m going to provide correct information regarding to PostgreSQL and MySQL.

In this post, I explain the replication of both databases.

Five years ago, I was interested in Postgres-XC , currenty called Postgres-X2, and made a multi-GTM (global transaction manager) system for it.

Though I had forgotten this work for a long time, I found its executable files from my old PC a month ago (unfortunately the source code of them was lost). They perfectly run, so I provide a Vagrant box to run my old program on your PC.