Q. If on every legal database instant, the two expressions generate the same set of tuples, the expressions are called as

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Q. State true or false: Selection operations are commutative

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Q. Which of the following operations are associative

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Q. Which of the following set operations is not commutative?

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Q. State true or false: The projection operation does not distribute over the union operation

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Q. If no rule can be derived from any combination of others then the set of rules is said to be ________

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Q. Theta join operations are

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Q. Which of the following operations is associative

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Q. Which of the following set operations does the selection operation distribute over?

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Q. State true or false: Multiple equivalence rules can be used one after the other on a query

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Q. Which of the following information does the database system catalog store?

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Q. Most databases store the distribution of values for each attribute as a __________

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Q. What is the function of the equi-width histogram?

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Q. What kind of a sample must be used for statistical analysis?

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Q. The ________ SQL command generates statistics on a particular relation

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Q. The union of all records satisfying the individual simple conditions Oi is called as ________

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Q. The intersection of all records satisfying the individual simple conditions Oi is called as ________

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Q. State true or false: Estimation of the size of the result of a join is not possible

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Q. Size estimation can be done for which of the following processes?

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Q. The size of a _____ is simply V(A,r) where r is the relation and A is a distinct value

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