I always use my customized statistics views shown below because the original ones provide only minimum information.

I show my tools in this post.

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.

In this week end, I tested PostgresPro’s pg_arman with ptrack. Speaking from the conclusion, it works well.

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.

I’ll demonstrate how to relocate a tablespace directory without the reconstruction of databases.

This post is a part of my document.

The XLOG data format has changed in version 9.5.

This post is a part of my document.

In version 9.5, management policy for WAL segment files has improved. PostgreSQL 9.5 always holds the appropriate number of WAL files in pg_xlog depending on server activity.

This post is a part of my document.

I briefly explain that how streaming replication works in the following.