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2 votes
2 answers
1
Consider a relational schema $S=(U,V,W,X,Y,Z)$ on which the following functional dependencies hold: $(U \rightarrow V, VW \rightarrow X, Y \rightarrow W, X \rightarrow U)$ Which are the candidate keys among following options? $UY, VY$ $UY, VY, XY$ $UYZ, VYZ, VWZ$ $UYZ, VYZ, XYZ$
asked Nov 20, 2020 in Databases jothee 124 views
0 votes
1 answer
2
In the context of concurrency control, a given pair of operations in a schedule is called conflict schedule if At least one of the operations is write operation Both the operations are performed on the same data item Both the operations are performed by different transactions Both the operations are performed on different ... $(b)$ and $(c)$ only $(a)$, $(c)$ and $(d)$ only $(c)$ and $(d)$ only
asked Nov 20, 2020 in Databases jothee 51 views
0 votes
1 answer
3
Match $\text{List I}$ with $\text{List II}$ Choose the correct answer from the options given below: $A-II, B-IV, C-III, D-I$ $A-IV, B-I, C-II, D-III$ $A-II, B-I, C-IV, D-III$ $A-III, B-IV, C-I, D-II$
asked Nov 20, 2020 in Databases jothee 49 views
0 votes
1 answer
4
Consider the following table structures related to a university for the below question. EMPLOYEE NAME VARCHAR (30) NOT NULL, EID VARCHAR (10) NOT NULL, DEPTNO INT (5) NOT NULL, HODEID VARCHAR (10), SALARY INT (10), PRIMARY KEY (EID), FOREIGN KEY (HODEID) ... 20,30,40); SELECT DISTINCT EMPID FROM PROJECTWORK WHERE PROJNO IN(20,30,40); SELECT DISTINCT EMPID FROM PROJECTWORK WHERE PROJNO=20,30,40;
asked Nov 20, 2020 in Databases jothee 80 views
0 votes
1 answer
5
Consider the following table structures related to a university for the below question. EMPLOYEE NAME VARCHAR (30) NOT NULL, EID VARCHAR (10) NOT NULL, DEPTNO INT (5) NOT NULL, HODEID VARCHAR (10), SALARY INT (10), PRIMARY KEY (EID), FOREIGN KEY (HODEID) REFERENCES ... $II$ are false Statement $I$ is correct but Statement $II$ is false Statement $I$ is incorrect but Statement $II$ is true
asked Nov 20, 2020 in Databases jothee 54 views
0 votes
1 answer
6
Consider the following table structures related to a university for the below question. EMPLOYEE NAME VARCHAR (30) NOT NULL, EID VARCHAR (10) NOT NULL, DEPTNO INT (5) NOT NULL, HODEID VARCHAR (10), SALARY INT (10), PRIMARY KEY (EID), FOREIGN KEY (HODEID) REFERENCES EMPLOYEE (EID), ... EID Choose the correct answer from the options given below: $a$ and $b$ only $a$ and $c$ only $b$ only $c$ only
asked Nov 20, 2020 in Databases jothee 38 views
0 votes
1 answer
7
Consider the following table structures related to a university for the below question. EMPLOYEE NAME VARCHAR (30) NOT NULL, EID VARCHAR (10) NOT NULL, DEPTNO INT (5) NOT NULL, HODEID VARCHAR (10), SALARY INT (10), PRIMARY KEY (EID), FOREIGN KEY (HODEID) REFERENCES EMPLOYEE (EID), FOREIGN ... correct answer from the options given below: $a$ and $b$ only $a$ and $c$ only $b$ and $c$ only $a$ only
asked Nov 20, 2020 in Databases jothee 32 views
0 votes
1 answer
8
Consider the following table structures related to a university for the below question. EMPLOYEE NAME VARCHAR (30) NOT NULL, EID VARCHAR (10) NOT NULL, DEPTNO INT (5) NOT NULL, HODEID VARCHAR (10), SALARY INT (10), PRIMARY KEY (EID), FOREIGN KEY (HODEID) REFERENCES EMPLOYEE (EID), ... ) Choose the correct answer from the options given below: $a$ and $b$ only $a$ only $b$ and $c$ only $c$ only
asked Nov 20, 2020 in Databases jothee 33 views
2 votes
5 answers
9
Every Boyce-Codd Normal Form (BCNF) decomposition is dependency preserving not dependency preserving need be dependency preserving none of these
asked Apr 2, 2020 in Databases Lakshman Patel RJIT 606 views
2 votes
2 answers
10
A functional dependency of the form $x\to y$ is trivial if $y\subseteq x$ $y\subset x$ $x\subseteq y$ $x\subset y\:\text{and}\:y\subset x$
asked Apr 2, 2020 in Databases Lakshman Patel RJIT 618 views
0 votes
3 answers
11
A primary key, if combined with a foreign key creates parent child relationship between the tables that connect them many-to-many relationship between the tables that connect them network model between the tables that connect them none of these
asked Apr 2, 2020 in Databases Lakshman Patel RJIT 352 views
0 votes
2 answers
12
Given the following relation instance: $\begin{array}{ccc} X & Y & Z \\ \hline 1 & 4 & 2 \\ 1 & 5 & 3 \\ 1 & 6 & 3 \\ 3 & 2 & 2 \end{array}$ ... $YZ \rightarrow X \text{ and } X \rightarrow Z$ $XZ \rightarrow Y \text{ and } Y \rightarrow X$
asked Apr 2, 2020 in Databases Lakshman Patel RJIT 147 views
0 votes
1 answer
13
Consider the schema $R=(\text{S T U V})$ and the dependencies $ S \rightarrow T, T \rightarrow U, U \rightarrow V$, and $V \rightarrow S.$ If $R=(R1 \text{ and } R2)$ be a decomposition such that $R1 \cap R2= \phi$ then decomposition is not in $\text{2 NF}$ in $\text{2 NF}$ but not in $\text{3 NF}$ in $\text{3 NF}$ but not in $\text{2 NF}$ in both $\text{2 NF}$ and $\text{3 NF}$
asked Apr 2, 2020 in Databases Lakshman Patel RJIT 207 views
1 vote
2 answers
14
Assume transaction $A$ holds a shared lock $R.$ If transaction $B$ also requests for a shared lock on $R.$ It will result in deadlock situation immediately be granted immediately be rejected be granted as soon as it is released by $A$
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 318 views
1 vote
1 answer
15
Given relations $R(w,x)$ and $S(y,z),$ the result of SELECT DISTINCT $w,x$ from $R,S$ $R$ has no duplicates and $S$ is non-empty $R$ and $S$ have no duplicates $S$ has no duplicates and $R$ is non-empty $R$ and $S$ has the same number of tuples
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 211 views
1 vote
2 answers
16
For a database relation $R(a,b,c,d)$ where the domains of $a,b,c$ and $d$ include only atomic values, only the following functional dependencies and those that can be inferred from them hold. $a \rightarrow c$ $b \rightarrow d$ The relation is in First normal form but not in second normal form Second normal form but not in third normal form Third normal form None of the above
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 224 views
2 votes
1 answer
17
Which of the following desired features are beyond the capability of relational algebra? Aggregate Computation Multiplication Finding transitive closure All of the above
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 270 views
0 votes
1 answer
18
When transaction $Ti$ requests a data item currently held by $Tj,Ti$ is allowed to wait only if it has a time stamp smaller than that of $Tj$ (that is $Ti$ is order than Tj). Otherwise, $Ti$ is rolled back (dies). This is Wait-die Wait-wound Wound-wait Wait
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 240 views
0 votes
2 answers
19
When transaction $Ti$ requests a data item currently held by $Tj,Ti$ is allowed to wait only if it has a timestamp smaller than that of $Tj$ (that is $Ti$ is order than Tj). Otherwise, $Ti$ is rolled back (dies). This is Wait-die Wait-wound Wound-wait Wait
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 243 views
0 votes
1 answer
20
Given relations $R(w,x)$ and $S(y,z),$ the result of SELECT DISTINCT $w,x$ from $R,S$ $R$ has no duplicates and $S$ is non-empty $R$ and $S$ have no duplicates $S$ has no duplicates and $R$ is non-empty $R$ and $S$ has the same number of tuples
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 185 views
0 votes
1 answer
21
0 votes
2 answers
22
0 votes
1 answer
23
Assume transaction $A$ holds a shared lock $R.$ If transaction $B$ also requests for a shared lock on $R.$ It will result in deadlock situation immediately be granted immediately be rejected be granted as soon as it is released by $A$
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 174 views
0 votes
1 answer
24
Table employees has $10$ records. It has a non-NULL SALARY column which is also UNIQUE. The SQL statement SELECT COUNT(*) FROM EMPLOYEE WHERE SALARY > ALL (SELECT SALARY FROM EMPLOYEE); $10$ $9$ $5$ $0$
asked Apr 1, 2020 in Databases Lakshman Patel RJIT 220 views
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