Hi Meena,
you'll find the answers to your question in the postgres doc's. I'd suggest
reading at least the Tutorial
(http://www.postgresql.org/idocs/index.php?tutorial.html). Some basic
concepts (postmaster, clients, architecture of postgres) are explained
there.
Answers to your questions about the postmaster process and users can be
found at the adminsitrators guide
(http://www.postgresql.org/idocs/index.php?admin.html) and the reference
manual (http://www.postgresql.org/idocs/index.php?reference.html)
I'll put some basic answers just here.
----- Original Message -----
From: " meena nimmagadda" <meenahere@lycos.com>
Subject: [GENERAL] need help
> Hi! I have some doubts on Postgres....
> Once we start a Postmaster process, will it keep running forever? How can
we restart/stop??(the commands???)
Yes, postmaster will run forever ... at least as long as you don't stop it.
You can use pg_ctl for starting and stoping the postmaster.
(http://www.postgresql.org/idocs/index.php?app-pg-ctl.html)
> Also, should we start the Postmaster only as the "postgres" superuser???
Yes, because this "masterprocess" is just a server. Other users can connect
to the database via clientapplications.
> Is it possible to have users for postgres database also....like in
linux....we have users?
Yes. You can create new users with createuser
(http://www.postgresql.org/idocs/index.php?app-createuser.html).
> What is the importance of users and superuser?
Users can connect to the database and retrieve / insert data (if this rights
are granted to the user). A superuser can create databases and other users.
> After I start Postmaster process, I am getting the following error:
> SetUserId: user 'postgres' is not in 'pg_shadow'.
> What does it mean? How do I avoid it? Because of this,I am not able to
create a database......after starting postmaster process.
You don't have a DB-user "postgres". Although this should have been done
automatically during installation, you can create the user with the
createuser command.
> Thanks,
> Meena.