Enterprise database system (EDS) is the key factor for any successful medium to large business organization. An efficient, reliable and secured EDS enables business organizations to be productive and profitable.
In this competitive business world, any large organization survivable largely depends on an efficient EDS. There is currently a lot of EDS available in the market such as Oracle.
Oracle is one of the market leading enterprise database systems dominating the market choice for many small and big enterprise applications example PeopleSoft, SAP and Siebel. Many organizations choose oracle as their primary database customize applications.
The promise of Oracle is to provide efficient system to manage large volume of data with high availability and security. Since its inception, Oracle has released several versions of its database. The latest version Oracle 12c is with the promise of more integration with cloud computing and streamlined security.
3. Overview of Oracle database system
Oracle, as an EDS, usually comprises of client-server components. From high level view, it usually has one database server and one or multiple clients or App servers (figure 1).
Figure 1 Client Server Architecture
4. Oracle server
This is the place where database resides. There are two major components of Oracle servers; these are Oracle Database and Oracle Instance.
4.1 Oracle Database
It consists of set of operating system files and other components where the actual data resides for example customer, product or orders. Among the other components, memory structures, disk resources, table space and background process.
It is important to note that these resources cannot be accessed by client directly. Client access these resources via Oracle Instance. One database can be connected by multiple instances but one instance cannot be connected with multiple Oracle database.
4.2 Oracle Instance
It consists of memory structure...