Q1.19

MCQMarks unknown

The relational algebra expression equivalent to the following tuple calculus expression: $\left\{t \mid t \in r \land \left(t[A] = 10 \land t[B]=20\right)\right\}$ is

(A)

$\sigma_{(A=10 \lor B=20)} (r)$

(B)

$\sigma_{(A=10)} (r) \cup \sigma_{(B=20)} (r)$

(C)

$\sigma_{(A=10)} (r) \cap \sigma_{(B=20)} (r)$

(D)

$\sigma_{(A=10)} (r) - \sigma_{(B=20)} (r)$

Loading…