I just reinstalled my Laptop and it now become Ubuntu 12.04 LTS, I love this.
After whole day of installing, finally I got my postgresql installed, it is a good time to record how to initialize password for new installed postgresql.

sudo -u postgres psql -c "ALTER USER postgres PASSWORD 'postgres';"

This will set your postgres USER’s password into postgres.

Then just use psql -U postgres -h to logon.

But if you encountered
sql: FATAL: password authentication failed for user "postgres"

then check the file /etc/postgresql/{VERSION}/main/pg_hba.conf:
There must be a line like this as the first non-comment line:
local all postgres ident
After this, remember to restart your postgresql.

For newer versions of PostgreSQL ident actually might be peer. That’s OK also.


04 March 2014