Querying Relational Databases

Databases are often drawn as gigantic disks. After designing the schema of a database using the data definition language.

The schema consists of the structure of the relations and the attributes of those relations. Then the database load up with the initial data. It is farily common the database to be loaded form data tat comes from outside source. THe data may be stored in files of some type, and then loaded into the database. Once the data is loaded, then there is bunch of tuples in the relation. Now the data can be queried and modified. This happens continuously over time as long as the database is in existence.

Queryies directly to the database happens through an application or a website. Questions can be ask to the database and answers received.

Tags: coding