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Home -> Community -> Usenet -> c.d.o.server -> Re: I still don't understand the database concept but
"Stephan Bressler" <stephan.bressler_at_siemens.com> wrote in message news:<b32cke$ske$1_at_news.mch.sbs.de>...
> Hi James,
>
> "oracle server" refers to an instance, i.e. a bunch of processes and memory
> structure. "database" is the data stored on disk, which is maintained by the
> server.
> I cannot think of a scenario in which an instance runs more that one
> database. Unless you use rac, there's always a 1on1-relationship between
> instance and database. Of cource, you can run several instance-database-pair
> on a single machine.
>
> Regards
> Stephan
>
> "James" <james_at_nothing.com> wrote in message
> news:1045731947.931056_at_ftp.adept.co.za...
> > Hi there
> > Thanks to everyone for help on my last posting (Database names?) but to a
> > certain extent it confused me more.
> >
> > Firstly I'm using Windows 2k and running Oracle 9 server
> >
> > I've read
> >
> http://download-west.oracle.com/docs/cd/A87860_01/doc/server.817/a76965/c01i
> > ntro.htm#12981
> > "Introduction to Oracle Server"
> >
> > From my understanding or this document: You have an Oracle Server, which
> has
> > databases. The Databases are made up of Logical and Physical structures.
> > A database is divided into logical storage units called tablespaces, which
> > group related logical structures together.
> > And Datafiles physically store the data of all logical structures in the
> > table space.
> >
> > Now the question I have is how do I find out all the names of these
> > databases? Forexample I know that the Database I created when I setup the
> > server is "Maindb". I only have one on my server but I want to know for
> the
> > situation where I could have multiple!
> >
> > Am I still missing the plot? Sorry that I'm just not understanding this
> > concept, but its probably my stupidity shining through! ( or my youth!)
> I'm
> > very new to Oracle and all you help is much appriciated.
> >
> > cheers
> > James
> >
> >
James, for each database created on your server under each Oracle Home look for a dbs directory. For each instance created they should be an init.ora file and within each init.ora file there should be a database= parameter.
If you connect to your instance you can query the v$parameter view to find parameter setting values, see Oracle 9 Reference manual. You can query dba_data_files for the tablespace_name and their associated physical file names.
The dictionary views are also documented in the Oracle 9 Reference manual.
If you are new to Oracle the best place to start is to read the Concepts manual; it is an excellent source for understanding the concepts of instances, databases, the datatypes, and object types used in Oracle. Move from there to the DBA Administration manual and next should probably come Backup and Recovery. After all that is a DBA's most important function: insuring a valid backup exists and knowing how to apply it if necessary.
HTH -- Mark D Powell -- Received on Thu Feb 20 2003 - 08:57:49 CST
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