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Relational Model

1.   What do you understand by the term relation?

Ans: A relation is used to represent information about any entity and its relationship with other entities in the form of attributes (or columns) and tuples (or rows). It comprises a relation schema and a relation instance.

2.   What is a relational database?

Ans: A relational database is a collection of relations (or two-dimensional tables) having distinct names. It is a persistent storage mechanism that conforms to the relational model.

3.   Illustrate the difference between relation schema and relation instance.

Ans: A relation schema (also termed as relation intension) depicts the attributes of the table. It consists of a relation name R and a set of attributes (or fields) ...

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