Problems with createdb in postgres

Question

I have to run a simulation with several postgresql databases spread on different machines which all of them are running linux.

I successfully compiled and built postgresql from the source code and I can also run the server, but when I try to create a new db with this command:

./postgresql/bin/createdb db1

I get this error:

createdb: could not connect to database postgres: FATAL:  role "giulio" does not exist

where giulio is my username to access all the machines.

On some machine it works while on other it does not. I really cannot figure out the root of the problem. I suppose it is something related with the access control of postgres.

I did several research on google but I was not able to found and to solve the problem.

Does anyone know how to get this work?

Thanks,

-Giulio

rsj · Accepted Answer · 2011-11-02 23:57:37Z

3

PostgreSQL has its own users and roles that are separate from that of your OS. Generally there is a dedicated super user, postgres. For user management info, look here:

http://www.postgresql.org/docs/9.1/interactive/user-manag.html

When executing postgres commands, you need to specify the user with the -U flag (unless you are already logged in as an existing db user). When you called the createdb script, because you didn't use the -U flag, the server assumed that the uid of the caller (giulo) should be used, but you didn't add a user "giulio" to the db, and hence the error message.

So execute the command as

./postgresql/bin/createdb -U postgres db1

and it should work. Then, later on, you may want to create other users and roles in your db rather than doing everything as the superuser.

answered Nov 2, 2011 at 23:57

rsj

7883 silver badges10 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

A.H. · Accepted Answer · 2011-11-02 23:58:15Z

I would assume that on the machines where the user "giulio" is already known, you executed initdb with exactly this user making him the DB superuser. A quote from inidb(1) (emphasis mine):

--username=username Selects the user name of the database superuser. This defaults to the name of the effective user running initdb. It is really not important what the superuser's name is, but one might choose to keep the customary name postgres, even if the operating sys‐ tem user's name is different.

On the other machines I assume you did execute initdb with another user, hopefully using postgres.

In order to get back on the standard track I propose, that you delete the database cluster on the machines where "giulio" is the superuser and setup a new database cluster using the standard postgres user. Then add another user "giulio". This will avoid more confusion down the road as some scripts/programs expect a superuser account named postgres.

maudulus · Accepted Answer · 2014-03-09 17:24:30Z

2

My answer was more simple...I realized I needed to just run the following:

brew install postgresql

then to check if it worked I ran:

which createdb

to check the file path and if it worked, and it had ! Hope this helps.

answered Mar 9, 2014 at 17:24

maudulus

11.1k11 gold badges85 silver badges121 bronze badges

Collectives™ on Stack Overflow

Problems with createdb in postgres

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related