Oracle Essentials [Electronic resources] : Oracle Database 10g, 3rd Edition نسخه متنی

Chapter 4. Data Structures

In previous chapters, we examined some distinctions between the
different components that make up an Oracle database. For example,
you've learned that the Oracle instance differs from
the files that make up the physical storage of the data in
tablespaces, that you cannot access the data in a tablespace except
through an Oracle instance, and that the instance itself
isn't very valuable without the data stored in those
files.

In the same way, the actual tables and columns within the database
are the entities stored within the database files and accessed
through the database instance. The user who makes a request for data
from an Oracle database probably doesn't know
anything about instances and tablespaces, but does know about the
structure of her data, as implemented with tables and columns. To
fully leverage the power of Oracle, you must understand how the
Oracle database server implements and uses these logical data
structures.