Define views in relational algebra, Database Management System

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Views in relational algebra:

1. Basic expression contains either

a) A relation in the database.

b) A constant relation.

2. General expressions are madde out of smaller sub expressions using

a) σ_p(E₁) select (p a predicate)

b) ∏s(E₁) project (s a list of attributes)

c) P_x(E₁)rename (x a relation name)

d) E₁∪E₂ union

e) E₁- E₂ set difference

f) E_1x x E₂ cartesian product

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