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Recent questions tagged database-normalization

0 votes
1 answer
1
Suppose the following functional dependencies hold on a relation $U$ with attributes $P,Q,R,S$, and $T$: $P \rightarrow QR$ $RS \rightarrow T$ Which of the following functional dependencies can be inferred from the above functional dependencies? $PS \rightarrow T$ $R \rightarrow T$ $P \rightarrow R$ $PS \rightarrow Q$
asked Feb 18 in Databases Arjun 672 views
1 vote
5 answers
2
Consider the relation $R(P,Q,S,T,X,Y,Z,W)$ with the following functional dependencies. $PQ\rightarrow X;\quad P\rightarrow YX;\quad Q\rightarrow Y; \quad Y\rightarrow ZW$ Consider the decomposition of the relation $R$ into the constituent relations according to ... , but $D_2$ is a lossless decomposition Both $D_1$ and $D_2$ are lossless decompositions Both $D_1$ and $D_2$ are lossy decompositions
asked Feb 18 in Databases Arjun 1k views
1 vote
2 answers
3
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 306 views
1 vote
3 answers
4
Let $R=(A,B,C,D,E,F)$ be a relation scheme with the following dependencies: $C\to F,E\to a,EC\to D, A\to B$. Which of the following is a key for $R$? $CD$ $EC$ $AE$ $AC$
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 323 views
0 votes
3 answers
5
For a database relation $R(a,b,c,d)$ where the domains of $a,b,c,d$ include only atomic values, only the following functional dependencies and those that can be inferred from them hold: $a\to c\\b\to d$ 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 these.
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 307 views
0 votes
2 answers
6
Normalization from which is based on transitive dependency is classified as: First normal form. Second normal form. Fourth normal form. Third normal form.
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 268 views
0 votes
2 answers
7
In functional dependency between two sets of attribute $A$ and $B$ then set of attributes $A$ of database is classified as: top right side down left side left hand side right hand side
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 906 views
0 votes
2 answers
8
Which one of the following statements about normal forms is FALSE? BCNF is stricter than $3$NF. Lossless, dependency-preserving decomposition into BCNF is always possible. Lossless, dependency-preserving decomposition into $3$NF is always possible. Any relation with two attributes is BCNF.
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 521 views
0 votes
2 answers
9
If attribute of relation schema $R$ is member of some candidate key then this type of attributes are classified as: atomic attribute candidate attribute non-prime attribute prime attribute
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 1.4k views
0 votes
2 answers
10
Process of analyzing relation schemas to achieve minimal redundancy and insertion or update anomalies is classified as: normalization of data. denomination of data. isolation of data. de-normalization of data.
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 1.4k views
1 vote
3 answers
11
Rule which states that addition of same attributes to right side and left side will result in other valid dependency is classified as referential rule inferential rule augmentation rule reflexive rule
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 267 views
0 votes
2 answers
12
If every functional dependency in set $E$ is also in closure of $F$ then this is classified as $FD$ is covered by $E$ $E$ is covered by $F$ $F$ is covered by $E$ $F$ plus is covered by $E$
asked Mar 31, 2020 in Databases Lakshman Patel RJIT 317 views
0 votes
2 answers
13
3 votes
5 answers
14
Which one of the following statements are not correct? $S1$: $3$NF decomposition is always lossless join and dependency preserving. $S2$: $3$NF decomposition is always lossless join but may or may not be dependency preserving. $S3$: BCNF decomposition is always lossless join and dependency ... but may or may not be dependency preserving. Only $S1$ Only $S4$ Both $S1$ and $S4$ Both $S2$ and $S3$
asked Mar 30, 2020 in Databases Lakshman Patel RJIT 1.3k views
1 vote
2 answers
15
Which of the following is TRUE? Every relation in $3$NF is also in BCNF A relation R is in $3$NF if every non-prime attribute of R is fully functionally dependent on every key of R Every relation in BCNF is also in $3$NF No relation can be in both BCNF and $3$NF.
asked Mar 30, 2020 in Databases Lakshman Patel RJIT 334 views
0 votes
4 answers
16
Consider the relational schema $R(A B C D)$ with following $FD$ set $F=\{A \to CE, B \to D, AE \to D\}$. Identify the highest normal form satisfied by the relation $R$. $2$NF BCNF $3$NF $1$NF
asked Mar 30, 2020 in Databases Lakshman Patel RJIT 1.6k views
0 votes
4 answers
17
Consider the relational schema $\text{R(A B C D)}$ with following functional dependency set $F=\{A\rightarrow BC,C\rightarrow D\};$ The relation $\text{R}$ is in $2$NF BCNF $3$NF $1$NF
asked Mar 30, 2020 in Databases Lakshman Patel RJIT 1.7k views
0 votes
6 answers
18
Which one is correct w.r.t. RDBMS? primary key $\subseteq$ super key $\subseteq$ candidate key primary key $\subseteq$ candidate key $\subseteq$ super key super key $\subseteq$ candidate key $\subseteq$ primary key super key $\subseteq$ primary key $\subseteq$ candidate key
asked Mar 24, 2020 in Databases jothee 482 views
0 votes
3 answers
19
For 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 are: $A \rightarrow C$ $B \rightarrow D$ The relation $R$ is in First ... well as in second normal form Second normal form but not in third normal form. Both in second normal form as well as in third normal form.
asked Mar 24, 2020 in Databases jothee 353 views
5 votes
2 answers
20
Consider a relational table $R$ that is in $3NF$, but not in BCNF. Which one of the following statements is TRUE? $R$ has a nontrivial functional dependency $X \rightarrow A$, where $X$ is not a superkey and $A$ is a prime attribute. $R$ has a nontrivial functional dependency ... $X$ is a proper subset of some key A cell in $R$ holds a set instead of an atomic value.
asked Feb 12, 2020 in Databases Arjun 2.4k views
4 votes
12 answers
21
If every non-key attribute functionally dependent on the primary key, then the relation will be in First normal form Second normal form Third normal form Fourth Normal form
asked Jan 13, 2020 in Databases Satbir 4.1k views
1 vote
0 answers
22
The process of normalization is used to Enhance the number of relations Determine the relationship between different relations Minimize the redundancies & eliminate anomalies Ease the computational work.
asked Aug 4, 2019 in Databases gatecse 80 views
0 votes
2 answers
23
The multivalued dependencies (MVDs) can be eliminated using ______ normal form on _____ normal form relations. $1$st, $2$nd $2$nd, $3$rd $3$rd, BCNF $4$th, BCNF
asked Aug 4, 2019 in Others gatecse 194 views
3 votes
5 answers
24
In relational databases, if relation R is in BCNF, then which of the following is true about relation R? R is in 4NF R is not in 1NF R is in 2NF and not in 3NF R is in 2NF and 3NF
asked Jul 2, 2019 in Databases Arjun 1.5k views
2 votes
4 answers
25
1 vote
2 answers
26
Consider the relation $R\left ( A,B,C,D,E \right )$ with functional dependencies $F=${ $A\rightarrow B$ $BC\rightarrow E$ $ED\rightarrow A$ } Number of additional relation required to convert it into lossless , dependency preserving $3NF$ decomposition is _____________ What is meaning of additional relation (Here no table mentioned previously)??
asked May 19, 2019 in Databases srestha 562 views
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