The dependency of an attribute on a set of attributes is known as trivial functional dependency if the set of attributes includes that attribute. Symbolically: A ->B is trivial functional dependency if B is a subset of A. The following dependencies are also trivial: A->A & B->B For exa...
What is Equivalence of Functional Dependencies in DBMS? In the context of databases,functional dependency is a relationship between two setsof attributes within a database table. It describes the dependency of one set of attributes, known as the dependent attributes, on another set of attributes, ...
What are Armstrong's Axioms in Functional Dependency in DBMS?Armstrong axioms are a complete set of inference rules or axioms, introduced and developed by William W. Armstrong in 1974. The inference rules are sound which is used to test logical inferences of functional dependencies. The axiom ...
Starting from SQL-99, the concept of “functional dependency” was introduced; a column B is functionally dependent on columns {A1, A2} in a result set if all rows which share the same value of A1 and the same value of A2 necessarily share the same value of B. Then ...
Trivial Functional Dependency Non-trivial Functional Dependency Both A and B None of the aboveAnswer: C) Both A and BExplanation:There are mainly four types of Functional Dependency in DBMS:Trivial functional dependency Non-Trivial functional dependency Multivalued functional dependency Transitive ...
DBMS - Aggregate Functions DBMS - Nested Queries, Correlated Nested Queries & Set Comparison Operators DBMS - Functional Dependency & Attribute Closure DBMS - Closure Set of Attribute DBMS - Codd's 12 Rules DBMS - Relational Algebra DBMS - Extended Operators in Relational Algebra DBMS - Relational...