OS: Linux Red-Hat 5.2
Oracle 11G R2 Standard Edition.

I am very new to Oracle (My backgroud is SQL Server/DB2) and I have been through a couple of documentation but I can not resolve my Enterprise manager problem.

We have 4 databases on this server (1 Oracle instance). I got their http address from the "REPOSITORY_URL" of the emd.properties files. The port numbers are:

1158
5500
5501
5502

When I put the url as https://server.ad.domain.netort/em

I can only get to the one with the port number 5500 and none of the others. I am loging in with oracle ID and my $ORACLE_HOME is set to

/u01/app/oracle/product/11.2.0/db_1

and my $ORACLE_SID is set to the database name with the only port number (5500) that allows me to get to the login screen.

All other databases, I get the "Unable to connect" error even though I change the $ORACLE_SID to their DbNames.

Can someone please tell me what configurations (to which files, environments, variables) have to be made to allow me to get to the login page of each database ? I have not created the databases so, I did not select any options while creating them.

Thanks in advance.

With Oracle you only have one database per instance. If you need 4 databases open simultaneously, you'll need to define and start 4 instances.

Thank you...........I guess it is not possible to run all 4 databases with one userid unless you manually change the oracle_sid and start/stop enterprise manager.

What is the best practice ?. Create a different user for each database ?

Thanks again.

1) EM is not required to run or manage any DB
2) if you want to be able to manage multiple DB, then buy EM Grid

then, what is used to run/manage databases other than EM Grid ? SQLPLUS ?

any sql client, like SQuirreL SQL Client Home Page, can be used.

Thanks.................