CAUTION The answer about changing the UNIX password for "postgres" through "$ sudo passwd postgres" is not preferred, and can even be DANGEROUS!
This is why: By default, the UNIX account "postgres" is locked, which means it cannot be logged in using a password. If you use "sudo passwd postgres", the account is immediately unlocked. Worse, if you set the password to something weak, like "postgres", then you are exposed to a great security danger. For example, there are a number of bots out there trying the username/password combo "postgres/postgres" to log into your UNIX system.
What you should do is follow Chris James's answer:
sudo -u postgres psql postgres
# \password postgres
Enter new password:
To explain it a little bit. There are usually two default ways to login to PostgreSQL server:
By running the "psql" command as a UNIX user (so-called IDENT/PEER authentication), e.g.: sudo -u postgres psql. Note that sudo -u does NOT unlock the UNIX user.
by TCP/IP connection using PostgreSQL's own managed username/password (so-called TCP authentication) (i.e., NOT the UNIX password).
So you never want to set the password for UNIX account "postgres". Leave it locked as it is by default.
Of course things can change if you configure it differently from the default setting. For example, one could sync the PostgreSQL password with UNIX password and only allow local logins. That would be beyond the scope of this question.
You're looking for one of the following commands:
SET SHOWPLAN_TEXT ON/OFF
SET SHOWPLAN_XML ON/OFF
SSMS also has features built into the GUI to display an estimated execution plan (but doesn't actually execute the query) as well as display the actual execution plan. They are separate options.
Best Answer
I'm not familiar enough with MySQL to know what the \G option does, but based on the documentation it looks like the psql \x option might do what you want.
It's a toggle, though, so you do it before you submit the query.