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Recent questions tagged database-normalization

1 vote
2 answers
1
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 in Databases Lakshman Patel RJIT 131 views
1 vote
2 answers
2
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 in Databases Lakshman Patel RJIT 179 views
0 votes
2 answers
3
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 in Databases Lakshman Patel RJIT 183 views
0 votes
1 answer
4
0 votes
1 answer
5
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 in Databases Lakshman Patel RJIT 157 views
0 votes
1 answer
6
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 in Databases Lakshman Patel RJIT 142 views
0 votes
1 answer
7
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 in Databases Lakshman Patel RJIT 112 views
0 votes
1 answer
8
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 in Databases Lakshman Patel RJIT 180 views
0 votes
2 answers
9
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 in Databases Lakshman Patel RJIT 123 views
0 votes
1 answer
10
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 in Databases Lakshman Patel RJIT 113 views
0 votes
1 answer
11
3 votes
4 answers
12
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 in Databases Lakshman Patel RJIT 540 views
1 vote
2 answers
13
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 in Databases Lakshman Patel RJIT 166 views
0 votes
3 answers
14
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 in Databases Lakshman Patel RJIT 345 views
0 votes
3 answers
15
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 in Databases Lakshman Patel RJIT 493 views
0 votes
6 answers
16
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 in Databases jothee 212 views
0 votes
3 answers
17
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 in Databases jothee 212 views
4 votes
13 answers
18
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 in Databases Satbir 2k views
0 votes
1 answer
19
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 104 views
3 votes
5 answers
20
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 993 views
2 votes
4 answers
21
1 vote
2 answers
22
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 411 views
0 votes
2 answers
23
Consider the following relational schemes: R(A, B, C, D, E, F) and S(A, B, C) with in the following functional dependencies: I. AB --> C II. C --> ABDE III. ADE --> F Assume {A,B} is the key for both schemes. Which of the following statements is true? R ... : only AB→ C is the relation for the S table, which satisfies BCNF properties. (So S is in BCNF) Please let me know if it is correct or not.
asked May 10, 2019 in Databases pritam946 227 views
4 votes
4 answers
24
Consider a relation $R\left ( A,B,C,D,E \right )$ and functional dependencies are $F=\left \{ AC\rightarrow B,C\rightarrow D,A\rightarrow E,C\rightarrow B \right \}$ Relation $R$ is decomposed into $R_{1}\left ( A,B,C \right )$ and $R_{2}\left ( C,D \right )$ Then Is it a lossless decomposition? I am getting doubt, how it can be not lossless decomposition?
asked Apr 28, 2019 in Databases srestha 343 views
0 votes
2 answers
25
0 votes
1 answer
27
Do we need to find closure of functional dependencies of original relation to check whether the decomposed tables are in 2NF . I know that we have to do the above process for 3NF and BCNF . If yes , please give a example where we need to do it
asked Mar 30, 2019 in Databases ashunimbz 93 views
0 votes
1 answer
28
Consider 2 tables R1 and R2 . If we perform a cross product between them the condition that should be satisfied for not generating spurious tuples is both should have a common element which should be a 1>primary key 2>candidate key 3>super key In one of the tables which of the three is correct??
asked Mar 19, 2019 in Databases Doraemon 83 views
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