How to set up Oracle Environment... ?

Question

I have a fresh copy of Oracle Enterprise Linux with Oracle 11g R1 installed.
Steps that I did and I am trying to understand……
1.     Boot the OEL server.
2.     From remote connection, using PUTTY, I connect to the OEL
3.     I am setting the variables(ORACLE_HOME & ORACLE_SID) with the ‘export’
4.     Login to sqlplus as sys with sysdba
5.     Started the database. Everything is fine!
6.     If I logout of PUTTY and log back all my step 3 variables are gone.
7.     You know now I can’t start the Oracle database without error.
My question is……
How to make the proper environment for Oracle database?
Do I have to have the above two variable populated all the time. Does these two variables need to be part of any login script (for root)? Once session (shell) has to be running all the time?
Missing the link here. I am learning.
Thank you,
Smith

Answer 1

For starters, there are several shell environments that you could have set as your default, such as: sh, csh, ksh, bash, tcsh, zsh, or rc.
Depending which shell environment you have set, you may or will have a different startup file when you login.
But the basics still apply:
For the most part, the first thing is that you should not be running anything as root (related to Oracle).
Oracle should have its own userid and be part of the DBA group.
Perhaps you mistyped.
Next, yes, your environment variables will need to be reset when you log back in.
There are a number of ways to accomplish this.
One of the most popular ways (although I don't necessarily agree), is to set the environment variables in your login startup script.
for example, your .profile (dot-profile). For ksh shell, for example, this is run at start up when you log in, after your session has read the /etc/profile script for system wide settings.
If the environment variables are set correctly, they are exported, which is sourced as your login script runs.
Alternately, (which I prefer), is you can 'source' the environment variables yourself.
This is done differently again depending on your default shell.
For ksh, you simply type . <shell script name>. (That is: dot-space-scriptfile)
It is important that you include a space between the dot and the file to be executed.
This will allow you to spawn additional windows from your main window and carry those env parameter settings forward.
Another option, preferred by Oracle, is that you set the Oracle $PATH in your login script (.profile or whatever), and then execute . oraenv. (dot-space-oraenv). This sources the parameters that are set when you run the oraenv which sets things such as your ORACLE_SID and ORACLE_HOME.
HTH...