Database Administration

Database Administration



Database Administration

Referring to the case of Easy Claim implementing he database systems (DBS) or the database management systems (DBMS) comprise of a collection of corresponding and persistent data, and is a set of application programs that is utilized to access, update and manage that data. The main aim of DBMS is to furnish an environment that is both convenient and effective to use in retrieving information from the database and storing information into the database. Usually, databases are intended to manage large bodies of information that comprise of definition of structures for information storage, data modeling, manipulation of information, file and systems structure, query processing, safety of information in the database, that is crash recovery and security and lastly the synchronous control if the system is shared by users. (Christopher Browne 2007 Pp. 42)

Goal

Basically, the rationale for the database system is to eliminate the problem that produced data repetition and discrepancy, and provide regular updates. DBMS is also intended to eliminate complication in accessing data. Like for example, the administrator may have to write a new application program to satisfy an unusual request like finding all customers with the same postal code, and this means big time consumption. Another purpose that is served is getting rid of data isolation, multiple user access, safety and integrity.

Purpose

Thus the main purpose of a database system is to furnish users with an abstract view of the system, that is system hides certain details of how data is stored and created and maintained thereby hiding the complex system structures. Basically, there are three many levels of abstraction. First is the physical level, that is the method of storing the data and is the lowest level of abstraction. The second level is the conceptual level that describes as to what data are stored and the relationship among the data. And the third level is the view level that describes the part of the database for a particular group of users.

Data Models

Data models are a set of abstract tools for describing data, data relationships, data semantics and data constraints. There are three distinct groups, the Object-based Logical Models, Record-based Logical Models and the Physical Data Models.

The Object-based Logical Models

Object-based logical models describe data at the conceptual and view levels and provide adaptable structuring capabilities, thereby letting one to enumerate data constraints explicitly. There are more than thirty such models that include Entity-relationship model, Object-oriented model, Binary model, Semantic data model, Infological model and the Functional data model. Two models are discussed here, the Entity-relationship model and the Object-oriented model. (Karney, James 2008 P. 120)

The E-R Model

The entity-relationship model is based on a collection of basic objects or entities and relationships between these objects. Each entity is described by a set of attributes and is associated or linked by a set of relationships. The set of all entities or relationships is termed as the entity set or relationship set. An essential element of the E-R model is the mapping cardinalities, which represent the ...