I have installed PostgreSQL for a long time but just currently learning it.
Here is what happened if I run psql in the command prompt
C:\Users\VandaRsq>psql
Password for user Vanda Rashq:
Since I forgot the password for the Vanda Rashq role but I remember for the postgres role, I run psql -U postgres.
I tried to list the role by using du command and the result is this:
I also tried using SELECT rolname FROM pg_roles command and yield:
I have tried to follow this tutorial and do ALTER USER "Vanda Rashq" WITH PASSWORD 'new_password'; but it returns ERROR: role "Vanda Rashq" does not exist
My question is, does the "Vanda Rashq" role actually still exist? If yes, how to reset (change) the password in case I forgot the password? If not, how to change the default role when running psql to postgres role
Notes: I have tried to uninstall the PostgreSQL and remove all of the directories but when I try to run psql, it still ask Password for user Vanda Rashq
If the user you're looking for is not listed after calling \du in psql then the user does not exist in the database.
Btw, you could also use a select to retrieve information about database users: select * from pg_catalog.pg_user;
EDIT:
Like #jjanes pointed out you get challenged for a password based on the USER configuration in yourpg_hba.conf (see docs).
For authentication method peer it is stated:
Obtain the client's operating system user name from the operating system and check if it matches the requested database user name.
I'm running postgresql 10.12 on Ubuntu 18.04.
I'd like to experiment with a software package that uses postgres. This means I should figure out how to set up users, passwords and databases under postgres.
Postgres is running, but there's no way to log in to it.
I'm pretty sure there is a user called 'postgres'.
Logging in as this user without providing a password fails.
Also, attempting to use the passwords 'postgres' or 'root' fail.
How do I change the password for the user 'postgres' without being able to access the database?
This is a newbie-level recipe to modify initial password, which works on all fresh installations of the postgresql package on Linux Debian/Ubuntu and derivatives.
Go to the shell and switch user to postgres
(in user shell) sudo su - postgres
connect to the postgres database as postgres user
(in postgres shell) psql postgres postgres
now you can modify password of postgres user
(in postgres psql) ALTER USER postgres PASSWORD 'newsecret';
quit psql
(in postgres psql) \q
quit postgres shell
(in postgres shell) exit
test connection with new password
(in user shell) psql -h localhost postgres postgres
Note on remote postgres servers
In step 1 above, you can use ssh or kubectl exec or anything like that, if you have this kind of access.
Best Practice note
Above recipe (though it answers the OP question) is not a good practice. The best approach is:
Read and understand client auth -> https://www.postgresql.org/docs/current/client-authentication.html
Do not use postgres database user (or any other superuser!) for applications/development. Create your own user instead. For the simplest setup, use this:
(in psql shell)
CREATE USER myapp PASSWORD 'secret';
CREATE DATABASE myapp;
ALTER DATABASE myapp OWNER TO myapp;
-- alternative if you want to keep default ownership:
-- GRANT ALL ON DATABASE myapp TO myapp;
This should be done instead of modifying postgres user and/or postgres database.
I'm trying to set up a Heroku environment for python development following instructions on https://github.com/heroku/python-getting-started. When I run createdb python_getting_started:
I'm first prompted to give in a password: I entered the password of the user "postgres" in Postgres
I get an error message:
createdb database creation failed: ERROR: permission denied to create database
Don't really how to solve this one. The user "postgres" is allowed to create a database. I checked with \du that it is a Superuser and it has Create DB rights. What's going on here? Which user is Windows using to try to create a Postgres DB?
Most PostgreSQL utilities by default use your current OS session login for database connections.
You need to either set environment variable PGUSER to postgres or use createdb -U postgres python_getting_started.
You can read more about createdb parameters here, tho admittedly it does not mention default values.
EDIT: It actually does mention that it uses libpq defaults, and those are:
user
PostgreSQL user name to connect as. Defaults to be the same as the operating system name of the user running the application.
I am pretty much confused about root user,super user,user and permissions! I am not able to create a database inside user "athleticu". Following are the commands I used:-
athleticu#ip-172-30-4-103:/home/ubuntu$ createdb -T template0 simple_db1
createdb: database creation failed: ERROR: permission denied to create database
athleticu#ip-172-30-4-103:/home/ubuntu$ sudo createdb -T template0 simple_db1
sudo: unable to resolve host ip-172-30-4-103
createdb: could not connect to database template1: FATAL: role "root" does not exist
Please somebody clarify my doubts and tell me what should I write!
Hey I have already solved this. What you have to do is to first login as postgres user as follows:
$ su postgres
$ psql
postgres=# alter user athleticu createdb;
ALTER ROLE
Hope it helps you :)
Type \du in psql and you will see a list of all the registered users and what type of privileges each one has.
In order to grant privileges to the user which is logged in (eg 'user1'), I had to sign out and log in using one of the superuser roles in that list (eg. 'user2'), using the following command:
psql -U 'user2' -h localhost 'database2'
where 'database2' is the name of the one that specific superuser 'user2' has privileges to.
Once you are logged in as a superuser, you can grant privileges to 'user1' by:
ALTER ROLE user1 WITH CREATEDB
or
ALTER ROLE user1 WITH SUPERUSER
Then sign in again as user1, who is now a superuser.
This blog was helpful as well as this link.
Currently, this worked for me:
sudo su postgres
psql
ALTER USER username WITH CREATEDB;
\q
exit
The root user is an account on the system independent from Postgres. There is only one root user.
A superuser is an account in Postgres with access to everything. There may be many superusers.
System accounts and Postgres accounts are different things, although unless you specify a Postgres username when you connect to the database (through utilities like psql, createdb, dropdb, or otherwise), it will use the current system user's name in hopes that there is a corresponding Postgres account with the same name. The root user does not, by default, have a corresponding account in Postgres.
When you install Postgres on *nix, it creates both a superuser named postgres and a system user named postgres.
Therefore, when you need to do something with Postgres as the built-in superuser, you have two options:
You may sudo su - postgres to become the postgres system user and execute your command (createdb, psql, etc). Because the system user has the same name as the database superuser, your command will connect as the appropriate account.
You may specify the username to execute as with the -U switch, eg psql -U postgres ....
Depending on your Postgres server's authentication settings, you may be required to enter a password with either or both connection methods.
What you can do when you have fresh installation of PostgreSQL is create your user with some rights (see createuser documentation):
my-user> sudo su - postgres -c "createuser <my-user> --createdb"
This will allow my-user to create DBs just like so:
my-user> createdb <my-db>
If you want the my-user to be able to do anything just use the --superuser flag instead:
my-user> sudo su - postgres -c "createuser <my-user> --superuser"
I got the same error and I found out that the reason was that I was trying to create a database outside of psql as a user which did not exist for postgresql. I found out about it and solved it by taking the following steps:
In my terminal I logged in as postgres user (the root user by default for postgresql) by typing sudo -u postgres psql
While inside the psql I typed \du to see all users and their privileges. I found out that I had only one user (the postgres one) and I had to create another superuser which had the same username as my Linux user (george)
I typed (still inside psql) CREATE USER george SUPERUSER; and this way I created a new super user called george.
I exited psql (by typing \q) and I was now able from outside psql, meaning from my terminal, to run created db <database name> with no issues at all.
Error ? You are trying to perform database actions( Creating Database, creating Roles) using a user that doesn't have the permission for those types of actions you are trying to perform.
solution ? Simply login to your database on the command line, i.e for PostgreSQL one will use "sudo -u postgres psql", then confirm that users specific assigned roles using the command "\du", most probably he/she doesn't have the necessary permissions to perform the actions you wanted. Then simply assign the roles you want the user to perform ,i.e create Database or simply make user "Superuser" by following along(https://chartio.com/resources/tutorials/how-to-change-a-user-to-superuser-in-postgresql/)
I am unable to create databases using my postgres client with the user I log in as.
I am having trouble figuring out how increase the privileges of my user. I have access to the linux server running postgres and am able to use psql to log on as my user and as the postgres user.
Can someone tell me what commands I should run to allow my user to create databases on my server through the postgres GUI running on a remote host?
Many thanks,
I don´t know of a postgres GUI, but here's how to do it in the psql-console (logged in as the superuser):
=> ALTER USER your_username CREATEDB;
See http://www.postgresql.org/docs/current/interactive/sql-alteruser.html for more info.