Before going for the database details, some confusion is cleared as follows.
Databases
A database is an organized collection of data including schemes, tables, queries, reports, views, & other objects. The data is organized to model aspects of reality in a way that supports processes requiring information, such as modelling the availability of rooms in hotels in a way that supports finding a hotel with vacancies.
| Databases are characterized by a three-schema architecture because there are three different ways to look at them. Each schema is important to different groups in an organization. The figure illustrates this architecture and the groups most involved with each schema. |
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Database Management Systems (DBMSs)
A DBMS is a computer software application that interacts with users, other applications, and database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases.
| Database management systems are often classified according to the database model that they support; the most popular database systems since the 1980s have all supported the relational model as represented by the SQL language. |
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