Database administrator, Database Management System

Database Administrator

One of the main perpose for having the database management system is to have control of both data or programs accessing that data. The person having like control over the system is called as the database administrator (DBA). The DBA administers the 3 stages of the database and tells the global view or conceptual level of the database. The DBA also displays the external view of the applications and several users and is responsible for the definition and execution of the internal level, as well as the storage structure and access techniques to be used for the optimum performance of the DBMS. A modification to any of the 3 levels due to varies in the organisation and/or emerging technology is under the control of the DBA.

Mappings among the internal and the conceptual levels, as well as between the conceptual and external levels, are also describe through the DBA. The DBA is responsible for granting permission to the users of the database and remainsthe profile of each user in the database. This profile defines the permissible activities of a user on that portion of the database accessible to the user through one or more user views. The user profile could be used by the database system to confirm in which a particular user can present a given operation on the database.

The DBA is also responsible for describing procedures to recover the database from natural, failures due to human, or hardware causes along  with minimal loss of data. This recovery procedure should permit the organisation to continue to function and the intact portion of the database has to continue to be available.

Therefore, the functions of DBA are:

  • Schema definition: Formation of the original database schema is accomplished through writing a set of definitions which are translated through the DDL compiler to a set of tables that are always stored in the data dictionary.
  • Storage Structure and access method definition: The Formation of appropriate storage structure and access techniques is accomplished through writing a set of definitions which are translated by the definition language compiler and data storage.
  • Schema and Physical organisation modification: DBA includes either the changes of the database schema or the description of the physical storage organisation. These changes, though relatively rare, are accomplished by writing a set of definitions which are used through  either the data storage or the DDL compiler and definition language compiler to make modification to the appropriate internal system tables (for example the data dictionary).
  • Granting of authorisation for data access: DBA allows the granting of different types of authorisation for data access to the various users of the database.
  • Integrity constraint specification: The DBA shows the constraints. These constraints are put in a special system structure, the data dictionary which is consulted through the database manager prior to any data manipulation. Data Dictionary is one of the precious tools in which the DBA uses to carry out data administration.
Posted Date: 3/5/2013 5:35:37 AM | Location : United States







Related Discussions:- Database administrator, Assignment Help, Ask Question on Database administrator, Get Answer, Expert's Help, Database administrator Discussions

Write discussion on Database administrator
Your posts are moderated
Related Questions
Explain I command in QBE ? I : It is the command in QBE that is used to insert tuple (s) into the database

What is inheritance? Define it in detail?  Inheritance Inheritance can be at the levels of types, or at the level of tables we first consider inheritance of types, then i

Define upgrade and downgrade? It gives a mechanism for conversion from shared lock to exclusive lock is called as upgrade. It gives a mechanism for conversion from exclusive

Data Control The data control mostly refers to commands that permit system and data privileges to be passed to several users. These commands are usually available to database admi

Differentiate between a subquery and a join If we need to acquire information from one or more tables after that either subquery or join can be used. If the columns which are t

Server Control It is usual to control access to the data via the front end application, for example by displaying data as ‘read only'. This part of the assignment illustrates ho

What is the use of Union and intersection operation? Union: The result of this operation contains all tuples that are either in r1 or in r2 or in both r1 and r2.Duplicate tuple

1. Will you advise that your organization uses open source software and why? 2. Why is it important for business managers to have a basic understanding of the software development

Natural Join : It is the similar like Equi join except one of the duplicate columns is removed in the result table. The natural join is the most usually used form of join operation

Rearrange Classes and Operations Sometimes, the similar operation is defined across different classes and can easily be inherited from a familiar ancestor, but more often oper