Chapter 8 - Components of a database system Flashcards
is a collection of interrelated data that can be process by one or more application system
Database
is information that is set up for easy access, management and updating. Computer databases typically store aggregations of data records or files that contain information, such as sales transactions, customer data, financials and product information.
Database
Reasons why is it necessary to have centralized customer database
Data independence
Shareability and Non redundancy
Integrity
relatability
Access flexibility
Security
performance and efficiency
Administration and control
the application program or users is protected from changes in the way that data is organized, stored, and accessed.
Data independence
all qualified users are assured access to required data via database.
Shareability and Non redundancy
the accuracy of the data must be ensured
Integrity
a records contains of information about an individual. Just as the data items on a single record are related to one another.
relatability
being able to easily and efficiently access the data in variety ways suited to the needs of the users.
Access flexibility
the database must be protected against unauthorized or malicious access and actions.
Security
the system must function smoothly at a level of cost that is acceptable to users.
performance and efficiency
there must be centralized authority and responsibility for the management of the system.
Administration and control
Components of Database System
Data-base management system
Users
database administrator
directory
Database
-is the heart of the system
-is software handles the request for data and performs other functions for user and system administrator.
Data-base management system
- represents the all the Individuals or groups who have access to data.
-users may access all or only a specific portion of data.
Users
- is the highly skilled technical specialist who acts as the main interface between the system and users.
-is responsible for the technical performance of the system, cooperating with the major user groups, for defining the data needs of organization and specifying how the data is configured to meet those need.
database administrator
- catalog all the data on the database. it stores definition each of data entity in the database
- it defines each item in terms of names, its length, and the form which is it stored.it stores data about relationship among data entities. (Data about data is called metadata) and also keeps track of a great deal of other data that enables users to access data quickly.
directory
- is a software system where the data are stored.
- there are several types of true database system, and also system that predate actual database system. there are also application programs, especially spreadsheet that have some of functionality but actually are not databases.
Database
3 primary types of database system
Hierarchical
Network
relational
- this database follows the progression of data being categorized in ranks or levels, wherein data is categorized based on a common point of linkage.
Hierarchical
- A database organized according to ownership of records, allowing records to have multiple owners and thus providing multiple access paths to the data.
Network
In this database, every piece of information has a relationship with every other piece of information. This is on account of every data value in the database having a unique identity in the form of a record.
relational
