PostgreSQL Basics — Series 2

Preview — 3 of 10 questions

What does \du show in psql?

javascript

List of roles
 Role name |                         Attributes
-----------+------------------------------------------------------------
 app_user  |
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS

ALists all database roles/users, along with their attributes (superuser, can login, etc.)

BLists all user-defined functions

CLists all UPDATE statements in the query history

DShows disk usage per table

What does \c mydb do in psql?

javascript

psql> \c mydb
You are now connected to database "mydb" as user "postgres".

ACreates a new database named mydb

BSwitches the current psql session's connection to the database named mydb

CCopies the current database to a new one named mydb

DChecks if a database named mydb exists, without connecting

What does \x toggle in psql?

javascript

psql> \x
Expanded display is on.

psql> SELECT * FROM users WHERE id = 1;
-[ RECORD 1 ]-------
id    | 1
email | alice@x.com
bio   | A very long bio field that would otherwise wrap awkwardly...

AWhether SQL keywords are highlighted in a different color

BWhether query execution time is shown after each query

CExtended (vertical) display mode, where each column of a row is printed on its own line instead of the default wide tabular format — useful for wide rows with many columns

DWhether NULL values are shown as empty strings or the literal text NULL

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