If you experience problems, then you'll need to double-check which version of the server you have. This will help you report a fault or to consult the correct version of the manual.
What version is the server?
How to do it...
We will find out the version by directly querying the database server.
Connect to the database and issue the following command:
postgres # SELECT version();
You'll get a response that looks something like this:
PostgreSQL 9.5.4 on x86_64-pc-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit
That's probably too much information all at once!