Off course to become an oracle DBA you should start your career with a solid IT background, Very good Oracle SQL, PL/SQL and Systems administration background as well as programming knowledge. To become a DBA at least you have good knowledge in all the three areas: Database itself either oracle or any other, a database Environment or Platform (OS) on which your database is running and the application, is using the database. In fact it is very difficult for a DBA having expertise in all aspects of DBA roles but I personally do not believe you just be a DBA without having expertise or at lease knowledge either system administration or database development. The admin knowledge focuses on system architecture, backup & recovery, Monitoring, Upgrade/Migrate, Patching etc. where as Developer knowledge DBA main focus on application architecture including designing, coding, business requirements and performance tuning.
The good news is that you can become an Oracle DBA but here is the truth of the matter: there are practically zero jobs for fresher or entry level DBA. In the oracle DBA entry level world at least they required 2-3 years experience candidate. Your IT certificate from local community college is practically nothing. In this case a certificate’s true value lies within helping you at least getting an interview call. It is very difficult for any company to hire fresher DBA as these works are fully related to responsibility as well as security so I would suggest if you are getting an entry-level job as a programmer/developer by making sure you get to work with Oracle then you can proceed your career here. The important thing is to make sure you let your employer know what your desired career path is so that they can support you in your efforts to get there. Initially take an interest on Monitoring acquire the knowledge to work with data dictionary view, make a good habit to play with SQL query, ideally you may find an entry level DBA position
Now start reading and learning on your own, make a habit to read Oracle Manual daily at least 1 hour, read oracle forum, Join oracle community make professional friends, do not hesitate to contact him ask good questions, and stay up to date. Once you are comfortable take the Oracle OCA exam, get certified and then apply for one or more entry level or junior DBA positions. Having the certification and good knowledge of Oracle will definitely give you that much needed edge to win the job.
Apart from the knowledge of the Oracle Database it is very important that you gain knowledge about the operating systems and the networking domains. It is an added advantage to have knowledge about the operating system, on which the database is mounted and running. Gaining some hands-on experience on the networking will also prove fruitful as DBA mostly works from a remote computer.
Initially, if anyone else solved errors then analysis it and try to apply on test environment yourself. The habit of using test environment will increase your confidence. Database Security is one of the prime responsibilities for DBA so it is my personal suggestion you must perform backup before doing any change in database. Here we will not forget the knowledge of application the database is using because your database performance is some how dependent on the application too.
Moving DBA to Apps DBA
Oracle E-Business is a suit of Business application made up of large number of distinct software module such as Oracle Financials, Oracle CRM, Oracle Supply Chain Application, Oracle Order Management and Human Resources (HRMS).
There are numerous Oracle Applications Modules offered with Oracle Applications thus the Oracle Applications DBA must have an understanding of the functional and internal aspects of the Oracle Applications software. For example: Oracle E-Business Suite (Oracle Financials) Apps DBA must have basic cost and financial accounting understanding.
Skills or Qualification:
The Oracle Applications DBA must have a good understanding of related technologies, especially Java (JDeveloper, J2EE, and Apache) and Oracle Application Server and for added advantage or successful career growth, it is essential to have either relevant degrees or diploma in business administration or very good understanding of business processes which help them to perform many of the duties of the oracle Apps DBA role.
In compare to Core DBA Apps DBA includes all the responsibilities of Core DBA plus Upgrade, Cloning, Patching thus moving to Apps DBA means working on broader technology. Most of the persons who are DBA and want to become Apps DBA are already expert in DBA activities, now they have to focus on architecture of application, how a service/component is working, Filesystem, Patching, Cloning and Troubleshooting.
There is enough opportunity in both the streams with good salary if you have right skills and good experience. It is quite difficult to compare salary and opportunity but in my views you have better prospects as Apps DBA as this include core DBA activities too.
Some of DBA Daily Maintenance Task:
1. Record maintain for Each Database Name and Instance Name Description.
2. Each Database Size.
3. Regularly Alert.log checking and if there is any issue try to short it out.
4. Tablespace Checking.
5. Schedule Export/Import Backup.
6. Schedule RMAN Backup.
7. Regularly Checking datafile increment and also checking auto-extensible or not.
8. Record the password for both sys and system schema.
9. schedule crontab job.
10. Checking OS space for Backup as well as other database drive location.
11. Checking Invalid objects.
12. Checking RAC status (if you have RAC Database).
13. Ensure that the archive redo log files are compressed and have been deleted. Only files for
current and previous day should be present.
14. Truncate the listener.log file in the $ORACLE_HOME/network/log location if the listener log has
increased to a size > than 500 MB. Ensure the space is released, otherwise ‘reload’ listener.
Note: It is always better if you automate most of above task. Do not depends on manual work.
If your organization already has some monitoring framework, configure oracle monitoring plugins/agents to check your databases.
Some Other Additional Task for a DBA:
1. Collect Statistics of database on regular basis. For Example: Collect table and index rows count,
2. Analyze schema and collect data.
3. Visit home page of key vendors. For Example:
4. Procedure to review contention for CPU, Memory, Network or disk resource.
5. Look for objects that break rules.
6. Rebuild indexes to have correct storage parameters.
7. All Tables Should have a unique Primary keys. find which primary keys are disabled.
8. All primary key indexes should be unique.
9. Copy Archived Logs to Standby Database and Roll Forward.
10. Read DBA manuals for one hour as a daily habits.
11. Look for security policy violations. for Example: SQL*Net logs for errors, issues.