chris webster wrote:Oracle RDBMS is the relational database management system i.e. the server software that manages your databases. It can manage several databases (and each database can hold many different schemas), and each database has a different SID. The SID i.e. "XE" or "SIVA" is the name of your database, which is used by Oracle's TNS listener program to connect you to the right database.
"XE" is the name of the database created by the lightweight Oracle Express Edition (XE) RDBMS, but as we discovered last week, Oracle XE 11g doesn't work on 64-bit Windows 7. Presumably you don't have a database called "XE" on your system, which is why the listener is giving you this error.
If you are following a tutorial, it may be expecting you to work with XE, but the same exercises will work on any Oracle database - you just need to specify the right database.
"SIVA" is presumably one of the databases you created last week on your standard Oracle RDBMS installation. If you have put your tables in the "SIVA" database, then you will need to connect to this database in order to work with your tables.
"ORCL" is the default database that gets created with the standard Oracle RDBMS. If you haven't created your schemas yet, or if you are going to use some of the standard Oracle sample schemas (e.g. HR), then you could just use ORCL for your work as it should contain the sample schemas and should have been created properly by Oracle during your installation process.
Incidentally, if you are using the browser-based Enterprise Manager "Database Control" tool (which will probably have a URL like https://localhost:1158/em) to manage your database, then you may find it points to the "ORCL" database by default, so any users etc that you create with this tool will be created in the ORCL database. This browser interface stinks and is way too complicated for newbies, so I recommend you just use SQL Developer for your work instead, as it's much easier and more flexible for you right now.
thanks chris.
as you said change the password of system and then login and user orcl as SID. i did so.
now i am getting this error. see attached screenshot
lalit