postgresql

1. initdb
	sudo -upostgres initdb -E UTF8 -k --locale=en_US.UTF-8 -D /var/lib/postgresql
	-L : used for init template, the default template init script is /usr/share/postgresql/postgres.bki
2. start service
	systemctl restart postgresql
3. createdb
	createdb -U postgres fsdb "main database for fusion splicer configuration"

	#note: if you can't start postgresql service in some cases, e.g. installing
	you can use following command to run postgresql under single user mode:
	su -l postgres -c "cat /mnt/data/initdb.sql | postgres --single -D /mnt/data
/database -j"

4. rebuild template1
	$ psql -U postgres postgres
	update pg_database set datistemplate = false where datname='template1';
	drop database template1;
	create database template1 template=template0;
	update pg_database set datistemplate = true where datname='template1';