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Computer Science
Computer Catlog
Oracle Catlog

History of Oracle
Introduction to Terms
Oracle Configurations
Roles of Database Administrator
Oracle Architecture
A Brief History of SQL
Dr. Codd's 12 Rules
An Overview of SQL
The SELECT Statement
Expressions, Conditions, and Operators
Functions
Clauses in SQL
Joining Tables
Sub Query
Manipulating Data
Building a Database
Views and Indexes
Controlling Transactions
Database Security
Advanced SQL Topics
Cursors
Stored Procedures
Triggers
Embedded SQL
SQL Tuning
Using Views in Data Dictionary
Using SQL to Generate SQL Statements

Roles of Database Administrator


    * If you want to become an Oracle DBA, you should first understand what an Oracle DBA's job is. The basic roles of the DBA are fairly consistent among different companies, but these duties might be expanded based on the size of the company and the experience of the DBA. In fact, the DBA is considered the main resource for DBMS experience and knowledge in many companies


    * Let's look at these roles and responsibilities and determine what skills are necessary to fulfill these duties. Here the roles and responsibilities are divided into two categories: basic duties and additional duties. The dividing line between these is not clear; there is significant overlap.

Basic Duties of the DBA


    * Here are some of the basic roles of the Oracle DBA. This is not an all-inclusive list. Depending on your installation and staff, your duties might not include all of these, or might include many more items. This section is simply intended as a general guide.

    * Installation of new software--It is primarily the job of the DBA to install new versions of Oracle software, application software, and other software related to DBMS administration. It is important that the DBA or other IS staff members test this new software before it is moved into a production environment.

    * Configuration of hardware and software with the system administrator-- In many cases the system software can only be accessed by the system administrator. In this case, the DBA must work closely with the system administrator to perform software installations, and to configure hardware and software so that it functions optimally with the DBMS.

    * Security administration--One of the main duties of the DBA is to monitor and administer DBMS security. This involves adding and removing users, administering quotas, auditing, and checking for security problems.

    * Performance tuning and monitoring--The DBA must continually monitor system performance and be prepared to retune the system as necessary. Even a well-tuned system must be constantly monitored and adjusted. Sometimes this involves changing tuning parameters, other times this involves rebuilding an index or restructuring a table.

    * Backup and recovery--Perhaps the most important responsibility of the DBA is protecting the data in the system. To effectively do this, you must develop an effective backup and recovery strategy and make sure it is carried out. A DBA's chief responsibility is to maintain the integrity of the database. It is important that the backup and recovery process be periodically tested.


    * Routine scheduled maintenance--It is the job of the DBA to schedule routine DBMS maintenance and carry out this maintenance. This maintenance is regularly carried out in the early hours of the morning or on weekends when this maintenance causes the least inconvenience to the user community.

    * Troubleshooting:--In the event of a system or DBMS failure, it is the job of the DBA to troubleshoot or assist in the Troubleshooting: of the problem. The DBA might also participate in or lead the effort to find and eliminate problems or potential problems.

    * Failure recovery--Because a system failure can mean that the users do not have access to their data, it can be the job of the DBA to lead efforts to recover from system failures. The well-prepared DBA has contingency plans for system outages and can soon have the DBMS running again.

Additional Duties of the DBA


    Some of the more advanced duties of the Oracle DBA might include the following:

    * Data analysis--The DBA will frequently be called on to analyze the data stored in the database and to make recommendations relating to performance and efficiency of that data storage. This might relate to the more effective use of indexes or the use of some feature such as the Parallel Query option.

    * Database design (preliminary)--The DBA is often involved at the preliminary database-design stages. Through the involvement of the DBA, many problems that might occur can be eliminated. The DBA knows the DBMS and system, can point out potential problems, and can help the development team with special performance considerations.

    * Data modeling and optimization--By modeling the data, it is possible to optimize the system layout to take the most advantage of your I/O subsystem.

    * Assisting developers with SQL and stored procedure development--The DBA should be prepared to be a resource for developers and users. The DBA is often called on to help with SQL problems as well as to design and write stored procedures.

    * Enterprise standards and naming conventions--Because many different groups might perform different roles in developing and deploying applications, it is often the DBA who is called on to help define enterprise standards and naming conventions as well as to ensure that new applications are conforming to these standards.

    * Development of production migration procedures--Because the DBA is responsible for the availability and reliability of the DBMS and applications using that DBMS, it is up to the DBA to develop and maintain procedures for rolling out new applications and DBMS software. This involves evaluating new software or patches as well as testing them. It is up to the DBA to guarantee the stability and robustness of the system.

    * Environmental documentation--The DBA should document every aspect of the DBMS environment, including hardware configuration and maintenance records, software updates, changes to the applications and DBMS, and all other items related to changes made to the system. The DBA should be able to access these records and fully reproduce the current system as necessary.

    * Consult with development team and end users--The DBA is often called on to act as a consultant to the development team as well as to the user community. This might involve personally assisting a single user or developing training courses for the user community as a whole.

    * Evaluation of new software--The DBA might be called on to evaluate new software and make recommendations based on that evaluation. This might be related to a software purchase or a scheduled rollout of a new version of software. This evaluation must be done in the context of the stability of the system. It is your responsibility to maintain system stability and reliability.

    * Evaluation of new hardware and software purchases--There is much consideration involved in purchasing new hardware and software. Much of this consideration involves the functionality and compatibility of the software or hardware as well as the cost of these components. Although the cost of the item is not usually a concern of the DBA, the functionality and compatibility is. The DBA might be asked to make recommendations based on whether these purchases make sense.

    * Capacity planning and sizing--Determining whether it is necessary to purchase new hardware or software to meet increased loads is often a job for the DBA. Capacity planning and sizing is important to provide the level of service your users require. By anticipating the future needs of your users, you can provide an excellent level of service with no interruptions.