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Consider two database relations R and S having 3 tuples in R and 2 tuples in S. what is the maximum number of tuples that could appear in the natural join of R and S?
Which one of the following provides the ability to query information from the database and to insert tuples into, delete tuples from, and modify tuples in the database?
Which of the following Relational Algebra operations can be used when you want to keep all the tuples of the first relation irrespective of whether or not they have matching tuples in the second relation?
Consider two relations R1(A, B) with the tuples (1, 5), (3, 7) and R2(A, C) = (1, 7), (4, 9). Assume that R(A, B, C) is the full natural outer join of R1 and R2. Consider the following tuples of the form (A, B, C): a = (1, 5, null), b = (1, null, 7), c = (3, null, 9), d = (4, 7, null), e = (1, 5, 7), f = (3, 7, null), g = (4, null, 9). Which one of the following statements is correct?
SQL allows duplicate tuples in relations, and correspondingly defines the multiplicity of tuples in the result of joins. Which one of the following queries always gives the same answer as the nested select * from R where a in (select S.a from S)
A ________ on an attribute of a relation is a data structure that allows the database system to find those tuples in the relation that have a specified value for that attribute efficiently, without scanning through all the tuples of the relation.
In a _____________ operations do not wait for requests to produce tuples, but instead generate the tuples eagerly.
Can a DFA simulate NDFA?
Is empty string a valid input in Ndfa.
Ndfa and dfa accept same languages.