Data files in Oracle are physical OS files attached to a database where
a user/schema may store tables and indexes. An application is typically
a schema/user in a database with privileges to store and retrieve data
in the database. An application can also be made up of more then one
schema/user, and it is not uncommon for several application interacting
with each other to co-exist as multiple schemas in one database and/or
multiple schemas in multiple databases. The Oracle RDBMS handles both
environment (quite an understatement).
The relationship between applications and physical file is:
a schema for an application exist in a database, with privileges to
store information in tablespaces which are made up of physical OS
files.
Note that a number of users/schemas (possibly bellonging to the same
application) may exist in the same database, and could have privileges
(quota) on the same or different tablespaces.
Going the other way, an OS file can only belong to one tablespace which
in turn can only belong to one database.
Also, a schema can only exist in one database. Another schema/user with
the same name can exist in another database but these two don't share
data. This is very common when you have a development database
mirroring the production database.
hth
Received on Tue Oct 31 2006 - 08:01:31 CST
