1
GATE CSE 2024 Set 1
Numerical
+1
-0.33

Consider the following two relations, R(A, B) and S(A, C):

R
AB
1020
2030
3040
3050
5095
S
AC
1090
3045
4080

The total number of tuples obtained by evaluating the following expression

$$\sigma_{B < C}(R \bowtie_{R.A = S.A} S)$$

is _________

2
GATE CSE 2022
MCQ (More than One Correct Answer)
+1
-0.33

Consider the following three relations in a relational database.

Employee ( $$\underline {eld}$$ , Name), Brand ( $$\underline {bld}$$ , bName), Own ( $$\underline {eld}$$ , $$\underline {bld}$$)

Which of the following relational algebra expressions return the set of elds who own all the brands?

A
$$\pi$$eld ($$\pi$$eld, bld (Own) / $$\pi$$bld (Brand))
B
$$\pi$$eld (Own) $$-$$ $$\pi$$eld (($$\pi$$eld (Own) $$\times$$ $$\pi$$bld (Brand)) $$-$$ $$\pi$$eld, bld (Own))
C
$$\pi$$eld ($$\pi$$eld, bld (Own) / $$\pi$$bld (Own))
D
$$\pi$$eld (($$\pi$$eld (Own) $$\times$$ $$\pi$$bld (Own) / $$\pi$$bld (Brand))
3
GATE CSE 2014 Set 3
+1
-0.3
What is the optimized version of the relation algebra expression $$\pi_{A1}(\pi_{A2}(\sigma_{F1}(\sigma_{F2}(r))))$$, where $$A1, A2$$ are sets of attributes in r with $$A1 \subset A2$$ and $$F1,F2$$ are Boolean expressions based on the attributes in r?
A
$$\pi_{A1}(\sigma_{(F1 \wedge F2)}(r))$$
B
$$\pi_{A1}(\sigma_{(F1 \vee F2)}(r))$$
C
$$\pi_{A2}(\sigma_{(F1 \wedge F2)}(r))$$
D
$$\pi_{A2}(\sigma_{(F1 \vee F2)}(r))$$
4
GATE CSE 2008
+1
-0.3

Which of the following tuple relational calculus expression(s) is/are equivalent to $$\forall t \in r \left(P\left(t\right)\right)$$?

I. $$\neg \exists t \in r \left(P\left(t\right)\right)$$
II. $$\exists t \notin r \left(P\left(t\right)\right)$$
III. $$\neg \exists t \in r \left(\neg P\left(t\right)\right)$$
IV. $$\exists t \notin r \left(\neg P\left(t\right)\right)$$
A
I only
B
II only
C
III only
D
III and IV only
GATE CSE Subjects
EXAM MAP
Medical
NEET