9-3
Database
9-3-1 Database architecture
A database is a collection of various data (information) organized and
stored in a single location according to a certain purpose. For example,
product or customer information is collected and stored together in a database.
Using a database enables business activities to be expressed from the perspective of information, and makes it possible to streamline those activities.
1
Characteristics of databases
A “database” is a collection of data organized for a certain purpose.
In the past, data used in business activities was saved in files according to
each program (process). In such a system, programs were created according to the data format. This resulted in the issue of programs not being able
to respond flexibly to changes in the format of the data. To resolve this
problem, databases were proposed.
A comparison of traditional files and databases is shown below.
Item
247
File
Database
Impact of changes to data
format on program
Large
Small
Redundancy of data
Data is sometimes redundant on a task-by-task basis
No redundancy
Consistency between related
data
Hard to maintain
Can be maintained
Sharing of data between tasks
Sharing is difficult
Sharing is easy
Data backup
Complicated
Simple and easy