What is Database and DBMS?

Database

A database is an integrated and self-describing collection of related data. Data is said to be integrated when you store it in a uniform method or format. Data is said to be self-describing when you store a descriptive tag along with it.

There are four commonly used types of databases. These are:
Database type…Average number of users…Database size….Description
Personal………..1……..10 MB…………..forms and reports
Work Group……25……100 MB.…………personnel connected by……….LAN use this database
Organizational…..hundreds…………………….1 trillion bytes….varied applications
Multimedia……….hundreds…………………..hundreds of MB….multimedia data

DBMS
A Database Management System (DBMS) is an application which you use to create and manage data in a database. In addition, you can use a DBMS to generate data outputs in a customized
format. Here is a diagram that shows a database system organization.

Benefits of DBMS

Transparent data management: You can store, retrieve, and update data in a single database. While managing data, you are not required to know the internal structure or functionality of the database.

Concurrent shared update: Two users working on the same data in a database can update that data at the same time. This also reduces data duplication and saves storage space.

Customized representation of data: You can use data from any number of files to create forms, reports, and other applications.

Restricted data access: You can use the security features of databases to provide access to authorized personnel. The security features that you can use are encryption, views,
authorization rules, and user-defined procedures.

Data independence and flexibility: The structure of a DBMS is independent of the data that you store in it. Therefore, you can create applications without much programming effort. When you access data from the database, you need to define only the data items that you require and not the data formats.

Database Design

There are five phases in the process of designing a database.

* Planning
* Analysis
* Design
* Implementation
* Maintenance

File Processing Systems - Limitations

In early file processing systems, information was stored as grouped records in different files known as flat files. For example, all information on inventory was grouped and stored in a single file. In this case, the programmers used programming languages such as COBOL to create applications to manage data and provide information to users. Here is a list of limitations of a file processing system.

Data duplication: Using groups of data resulted in storing same information in more than one file.
Isolated data: Because data was grouped and stored in separate files, you had to determine the data required from each file and the relationships between the data. You could then write
applications in a third generation language to process and retrieve the required data.

Data inflexibility: Data isolation and program-data interdependency limited the flexibility of file processing systems in providing users with ad hoc information requests.

Difficult to represent data: Data from different files was combined to create applications for users. It was difficult to determine relationships between isolated data to meet user requirements.

Data interdependence: Files and records, in a file processing system, were defined by specific formats coded into the application program by programmers. If the format of a record
was changed, the code in each file that contained the changed format must be updated.

Appropriate Use for a Database

You can use a database for its performance, expandability, flexibility, and scalability. Using a database, you can enforce standards and reduce application development time.
However, you should consider the high initial cost and overhead of using a DBMS.

There are certain situations when a DBMS is not appropriate.

These are when:
- Database is small with a simple structure.
- Applications are simple.
- Multi-user access to data is not required.