Database or database part 2

In one file there are records of the same kind, the same size, the same form, which is a set of uniform entities. A record consisting of an interconnected field indicates that the field is in one complete sense and recorded in a single record. Each field value or content has the same space or width capacity. The type of data content of a field must match its data type. The name of a file should describe the contents of the data file. To complete the definition of a file, in the database known entity names (entities) and attributes. Entetis is the person, place, event, or concept whose information is recorded. each entity has an attribute or a title to represent an entity. For example in a lecture system; mahasiwa, course, payment, lecturer is as entity. Whereas student entity has attribute of parent number, name, department, and so on. Or from the above example the entity is an employee, ang has NIP attribute, name, address, tgl_lahir, jns_kel The database system is a combination of database and database management system (SMBD). A complex database and accompanied by documentation techniques and manipulation procedures will establish a Database Management System (DBMS). In short the DBMS is a database and a program to access it.

The above definition can illustrate to us that the database has several important criteria, namely:

>Data-oriented and not program-oriented.
>Can be used by some application programs without needing to change its data base.
>Can be developed easily, both volume and structure.
>Can meet the needs of new systems easily.
>Can be used in different ways.

The components of the database system are:

>Hardware, as a support for data processing operations such as CPU, memory, disk, terminal, and so forth.
>Software operating system, (Windows 9x, Windows 2000 / XP, Linux, Unix.)
>Database management software (DBMS) such as MS-Access, SQL, Oracle.
>Software application programs such as Visual Basic, Delphi, Visual Foxpro.
>Database (all data required, maintained, managed by Database system)
>User / user database (user).

User (user) database includes:

>Database Administrator, a user who has authority as a central controller of all systems both database and programs that access it, determine the pattern of database structure, modify, divide processing tasks and provide a certain orientation, and so on.
>Aplication Programmers, an application programmer that interacts with the system through a Data Manipulation Language (DML) invocation entered into a write program.
Sophisticated Users, ie users who berintraksi with tapa system must write their own program, but replaced with a request (request) in the form of database query language. Such as using MS-Accsess, SQL, and so on.
>Specialized Users, users who write special database application programs that do not fit the traditional data processing framework. Examples: expert system, multimedia, and so forth.
>Naive Users, ie most users who mengintraksi with the system by calling one of the application programs that have been provided. Example: the operator on the teller, personnel, and so forth.

THE ROLE OF DATA BASES The data base is important in the management of data in using the computer, because bebrapa reasons are:

>As a major component or important in information systems, as it is the basis for providing information.
>Determine the quality of information fast, accurate, relevant, so that the information presented is not stale.     Information can be said to be worth when the benefits are more effective than the cost of getting it.

Preparation of a database is used to overcome the problems on the preparation of data. Benefits derived from the preparation of the database are to:

>Addressing data redundancy. The same data storage in some places besides can make it difficult for the user about data actualization also wasting the storage place, then the database will detect and avoid in case of data kerangkapan.
>Avoiding data inconsistencies. Another consequence if there is data kerangkapan, then if there is a change in the data one while the other is not changed will occur data inconsistency. For that the database will adjust to the same data in case of changes, if all data will always be updated
>Overcoming difficulties in accessing data. Facilitate if one day will be taken or printed data that has certain criteria, for example on a certain date, a particular address, a certain amount, and so forth.
>Formulate the standard format of a data. Dta ayang same on different files must have the data format of the type and the range should be the same. The inequality of the data format will result in difficult or inefficient access to other data.
>Usage by multiple users. A database can be utilized simultaneously by multiple users (multiuser)
Conducting protection and data security (data security). Any data can only be accessed over manipulated by the authorized party by providing login and password to each data.
>Develop data integrity and independence. The database is complex data that can be integrated, so we can manipulate to get various forms of worksheets and reports we want. However, each data is not interdependent on other data. The data in the database can stand on their own.