upgrade_postgres_91_93_debian

#!/bin/bash

# Update and upgrade packages
sudo apt-get update && sudo apt-get upgrade

# Install postgres 9.3
sudo apt-get install postgresql-9.3 postgresql-server-dev-9.3 postgresql-contrib-9.3

# Having Postgres 9.1 already, this will create database instance configured to run on port 5433

sudo service postgresql stop

# For pg_upgrade to work, you must switch to postgres user
sudo su - postgres
/usr/lib/postgresql/9.3/bin/pg_upgrade -b /usr/lib/postgresql/9.1/bin -B /usr/lib/postgresql/9.3/bin -d /var/lib/postgresql/9.1/main/ -D /var/lib/postgresql/9.3/main/ -O "-c config_file=/etc/postgresql/9.3/main/postgresql.conf" -o "-c config_file=/etc/postgresql/9.1/main/postgresql.conf"


# Start postgres
sudo service postgresql start

# Must link conf file into data directory since it's expected there by pg_upgrade.
# Unfortunately, Ubuntu places it in /etc default (which complicates the upgrade)
ln -s /etc/postgresql/9.1/main/postgresql.conf /var/lib/postgresql/9.1/main/postgresql.conf
ln -s /etc/postgresql/9.3/main/postgresql.conf /var/lib/postgresql/9.3/main/postgresql.conf
 
# Change user login method from `peer` to `trust`
sudo vim /etc/postgresql/9.1/main/pg_hba.conf
sudo vim /etc/postgresql/9.3/main/pg_hba.conf

# Run the pg_upgrade, but as the postgres user instead of root.
su postgres
cd ~postgres
/usr/lib/postgresql/9.3/bin/pg_upgrade -d /var/lib/postgresql/9.1/main -D /var/lib/postgresql/9.3/main -b /usr/lib/postgresql/9.1/bin -B /usr/lib/postgresql/9.3/bin -k -v
exit

# Change user login method from `trust` to `md5`
sudo vim /etc/postgresql/9.1/main/pg_hba.conf
sudo vim /etc/postgresql/9.3/main/pg_hba.conf

# check if the right port is configured: 5432
sudo vi /etc/postgresql/9.3/main/postgresql.conf
# Hopefully upgrade finished without error! In which case, we can start up PostgreSQL...
sudo /etc/init.d/postgresql start 9.3

# now we can remove postgresql 9.1
 sudo apt-get remove postgresql-9.1

# check if everything still works;
sudo /etc/init.d/postgresql restart