a) Selection operation b) Primitive operation c) Projection operation d) Generalized selection Answer: d Explanation: Generalization Selection ...
View QuestionThe ___________ operation, denoted by −, allows us to find tuples that are in one relation but are not in another.
a) Union b) Set-difference c) Difference d) Intersection Answer: b Explanation: The expression r − s produces a relation ...
View QuestionFor select operation the ________ appear in the subscript and the ___________ argument appears in the paranthesis after the sigma.
a) Predicates, relation b) Relation, Predicates c) Operation, Predicates d) Relation, Operation Answer: a Explanation: ...
View QuestionWhich of the following is used to denote the selection operation in relational algebra?
a) Pi (Greek) b) Sigma (Greek) c) Lambda (Greek) d) Omega (Greek) Answer: b Explanation: The select operation selects ...
View QuestionWhich of the following is a fundamental operation in relational algebra?
a) Set intersection b) Natural join c) Assignment d) None of the mentioned Answer: d Explanation: The ...
View QuestionRelational Algebra is a __________ query language that takes two relations as input and produces another relation as an output of the query.
a) Relational b) Structural c) Procedural d) Fundamental Answer: c Explanation: This language has fundamental and other operations which are ...
View QuestionWhich of the following is a legal expression in SQL?
a) SELECT NULL FROM EMPLOYEE; b) SELECT NAME FROM EMPLOYEE; c) SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL; d) None ...
View QuestionThe full form of DDL is
a) Dynamic Data Language b) Detailed Data Language c) Data Definition Language d) Data Derivation Language Answer: ...
View QuestionWhich of the following is an advantage of view?
a) Data Security b) Derived columns c) Hiding of complex queries d) All of the above Answer: d
View QuestionWhich of the following operations need the participating relations to be union compatible?
a) UNION b) INTERSECTION c) DIFFERENCE d) All of the above Answer: d
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