Executado em um ambiente Ubuntu
# remove PostgreSQL
echo "Removendo PostgreSQL..."
dpkg -l | grep postgres | awk '{print $2}' | xargs -r sudo apt-get purge --auto-remove -y
rm -rf /var/lib/postgresql/
rm -rf /var/log/postgresql/
rm -rf /etc/postgresql/
rm -rf /etc/postgresql-common/
rm -rf /usr/lib/postgresql/
sudo deluser --remove-home postgres 2>/dev/null || true
sudo delgroup postgres 2>/dev/null || true