Re: Another Database

In oracle terms, a database is a collection of files all managed by a series of oracle processes. The information about these files are stored in a series of tables, owned by the oracle user SYS. This is refered to as the data dictionary. There can be one and only one "instance" per machine for a single set of files. Oracle does support the Parallel Server Option, which allows for more than one system (machine) to access that same set of files from different machines, thereby having multiple instances accessing the same "database". A database is made up of multiple schemas, all of which have the possiblity, given they are granted the appropriate privledges, to create their own set of tables. These schemas also have the ability to reference, and access the other schema's in the same database. They can also access schema's in other databases, through network connections, refered to as database links, but referencial integrity is not possible across a link.

It is also possible to create multiple databases on a single machine, thereby having multiple oracle processes, accessing different sets of files. This is where it starts to get a little more involved than is possible in a NG. I will say, that it is no harder to create more than one oracle database, than it is to create one.

--
Robert Fazio, Oracle DBA
rfazio_at_home.com
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"Yoav" <i_yoav_at_hotmail.com> wrote in message
news:393b69bf_at_news.barak.net.il...


> Hi,

>

> First of all, I'm not a DBA so the question might sound absurd but...

>

> Could there be 2 database of oracle residing on the same machine? or does

 it


> mean simply 2 services, what does it mean another database on the same

> machine is there something like that?

>

> where can I find documentation explaining this? tried the TechNet, but did

> not find nothing...

>

> thanks

>

> Y.

>

>