Upgrade postgresql from 9.3 to 9.5 in Ubuntu 16.04 LTS

To see if your database is still on your server check this folder :

ls /var/lib/postgresql/9.3/main/base/

If you have files there, this mean your database is still here !!If nothing in this folder, this mean your life data have been deleted.

Did you made a regular backup of your database ?

If so, you need to install back your previous version of PostgreSQL and make a restore of it.

apt-get install postgresql-9.3psql -h localhostcreate database dbname;psql -h localhost dbname < backup_file

After the normal process to upgrade on Debian or Ubuntu is this one :service postgresql stop

On vire le clus­ter de la nouvelle version (norma­le­ment vide si on vient juste de l’ins­tal­ler : faire gaffe à ne pas lais­ser passer de temps entre l’ins­tal­la­tion de la nouvelle version et la migra­tion des données, pour que personne n’uti­lise le nouveau clus­ter)

Stop the new updated version of PostreSQL :

service postgresql stop

Drop the new updated version cluster to be sure nothing is inside :

pg_dropcluster --stop 9.5 main

Then data migration :

pg_upgradecluster -m upgrade 9.3 main

Then stop previous version of PotsgreSQL :

pg_dropcluster 9.3 main --stop

Remove the old version :

apt-get autoremove --purge postgresql-9.3 

Then just restart PostgreSQL, the new version with database migrated :

service postgresql start

Hope this help.

But if you didn't do any backup, unfortunatly you should have loose everything.