Database System(Will upload more later)

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Database System

   Database is information management system that let users able to use information of any work together, without information being complicate, and help user avoid the dissent of those information, also, information in system must be reliable, the same standard, by identify the information security.

   Nowadays, information is known as standard data, can be use to benefit in many ways, whether for business, management and other works.

   Organizations that have large amount of data find it's hard to manage them all, including when it's come to use, so Computer become the equipment for data management since then.

   However, each program must created control and management method itself, so database become necessary, especially for the work systems that need Computer. Therefore, design and development of database system should be about control and management of information using.

What is Database System

   Database System is an information structure that has detail of data, which relating to use along with various system.

   Users can storage data in many ways, therefore, they are able to add, edit, delete and view those data, which mostly are application of Computer system that use for data management.

Definition

- Bit 

   Is the smallest unit.

- Byte

   An unit that added many bits together and then became Character.

- Field

   An unit that consist of more than one characters, then got a meaning of something identity, e.g. name, address, etc.

- Record

   Unit from many field data assemble together, for example, 1 record of student, which content:
1. Student ID; 1 record
2. Student name; 1 record
3. Address; 1 record
- File
   Unit that assemble from many records(with the related data).

Other definition

- Entity
   Is the name of something, for example, people, place, etc.
- Relationships
   Is about relationship of entity, such as, student entity and subject entity.

Relationships between entity

   There are 3 types of relationship between entity.

1. One-to-one relationships (1:1)

2. One-to-many relationships (1:m)

3. Many-to-many relationships (m:n)

Importance of database processing

1. Reduce data redundancy.

2. Avoid data inconsistency.

3. Able to use data together.

4. Keep data reliable

5. Able to set data the same standard

6. Data security

7. Freedom of using data

Type of Databases

1. Relational database

2. Network database

3. Hierarchical database

Popular database program

- Access

- FoxPro

- dBase

- SQL