Friday 12 September 2014



What is DBA?
(Shubham Mehta,bca 3rd sem.,aug 2014)
A Database Administrator, Database Analyst or Database Developer is the person responsible for managing the information within an organization.
A database administrator (DBA) directs or performs all activities related to maintaining a successful database environment.
Centralized control of the database is exerted by a person or group of persons under the supervision of a high-level administrator. This person or group is referred to as the database administrator (DBA). They are the users who are most familiar with the database and are responsible for creating, modifying, and maintaining its three levels.
Database Administrator is responsible to manage the DBMS’s use and ensure that the database is functioning properly.
DBA administers the three levels of database and consultation with the overall user community, sets up the definition of the global view of the various users and applications and is responsible the definition and implementation of the internal level, including the storage structure and access methods to be used for the optimum performance of the DBMS.
DBA is responsible for granting permission to the users of the database and stores the profile of each user in the database.

The people responsible for managing databases are called database administrators. Each database administrator, dubbed DBA for the sake of brevity, may be engaged in performing various database manipulation tasks such as archiving, testing, running, security control, etc., all related to the environmental side of the databases. Their job is very important, since in today's world, almost all of the information a company uses is kept in databases.

A database administrator makes sure that database have the fo;;owing qualities:
1)      Data remains consistent across the database;
2)      Data is clearly defined;
3)      Users access data concurrently,in a form that suits their needs;
4)      There is provision for data sucrity and recovery control (all data is reterivable in an emergency)
A database administrator (acronym DBA) is an IT Professional responsible for the installation, configuration, upgrading, administration, monitoring, maintenance, and security of databases in an organization.





Database Administrator responsibilities

          Deciding the information content of the database :-

It is the DBA’s job to decide exactly what information is to be held in the database - in other words, to identify the entities of interest to the enterprise and to identify the information to be recorded about those entities. Having done this, the DBA must then define the content of the database by writing the conceptual schema.


          Deciding the storage structure and access strategy :-

The DBA must also decide how the data is to be represented in the database, and must specify the representation by writing the storage structure definition. In addition, the associated mapping between storage structure definition and the conceptual schema must also be specified.

          Liaising with the users:-

It is the business of the DBA to liaise with users, to ensure that the data they require is available, and to write the necessary external schemas. In addition, the mapping between any given external schema and the conceptual schema must also be specified. In practice the external DDL will probably include the means for specifying the mapping, but the schema and the mapping should be clearly distinguishable.

          Defining authorization checks and validation procedures

Authorization checks and validation procedures may be considered as logical extensions of the conceptual schema. The conceptual DDL will include facilities for specifying such checks and procedures.

          Defining a strategy for backup and recovery:-

Once an enterprise is committed to a database, it become critically dependent on the successful operation of that system. In the event of damage to any portion of the database – caused by human error, say, or a failure in the hardware or supporting operating system – it is essential to be able to repair the data concerned with a minimum of delay and with as little effect as possible on the rest of the system.

          Monitoring performance and responsibilities to changes in requirements

The DBA is responsible for so organizing the system as to get the performance that is “best for the enterprise” and for making the appropriate adjustments change. Any change to details of storage and access must be accompanied by a corresponding change to the definition of the mapping to storage, so that the conceptual schema may remain constant.
Database administrator responsibilities:-
Scope of Work
1. Database Installation and upgrading
2. Database configuration including configuration of background
processes
3. Database performance optimization & fine tuning
4. Configuring the Database in Archive log mode
5. Maintaining Database in archive log mode
6. Devising Database backup strategy
7. Monitoring & checking the Database backup & recovery process
8. Database troubleshooting
9. Database recovery incase of crash
10. Database security
11. Enabling auditing features wherever required
12. Table space management
13. Database Analysis report
14. Database health monitoring

Skills
List of skills required to become database administrators are:[3][4][5]
  • Communication skills
  • Knowledge of database theory
  • Knowledge of database design
  • Knowledge about the RDBMS itself, e.g. Oracle Database, IBM DB2, Microsoft SQL Server, Adaptive Server Enterprise, MaxDB, PostgreSQL
  • Knowledge of Structured Query Language (SQL) e.g. SQL/PSM, Transact-SQL
  • General understanding of distributed computing architectures, e.g. Client/Server, Internet/Intranet, Enterprise
  • General understanding of the underlying operating system, e.g. Windows, Unix, Linux, z/OS
  • General understanding of storage technologies, memory management, disk arrays, NAS/SAN, networking
  • General understanding of routine maintenance, recovery, and handling failover of a Database

REFRENCE:-
http://en.wikipedia.org/wiki/Database_administrator
http://ecomputernotes.com/fundamental/what-is-a-database/what-is-dba
http://www.ntchosting.com/databases/database-administration.html

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