> Now during installation, the user 'postgres' will be created if it doesnt
> already exist. And these 2 users (user1, postgres) will have write
> permissions to each other's home directories.
>
>
> Please tell me if my understanding so far is correct and if you can
> enlighten me further.
I think there might be some confusion over your use of the word
"user". There are two main types of users when we talk about
postgresql. There's system users and database users. System users
typically have a login and a shell on the operating system. Postgres
needs at least one system user to launch the database process. The
database files should be owned by only this user.
Database users do not need a login and shell on the operating system.
Instead they connect to postgresql using tcp/ip or some other means
and can interact with the database that way. This user does not need
to have a shell account or permissions to the filesystem where the
database files are located.
Typically, you'd install postgresql and have the postgres user run the
server process. Then you'd create database users that can access the
functionality of the database. Just like with Apache Web Server, there
is the apache user which starts the server process while you can
control web page access using HTTP Basic authentication via a htpasswd
file. These users are not "system" users.
AJ