Select the ‘False’ statement from the following statements about Normal Forms: (A) Lossless preserving decomposition into 3NF is always possible (B) Lossless preserving decomposition into BCNF is always possible (C) Any relation with two attributes is in BCNF (D) BCNF is stronger than 3NF

Select the ‘False’ statement from the following statements about Normal Forms: (A) Lossless preserving decomposition into 3NF is always possible (B) Lossless preserving decomposition into BCNF is always possible (C) Any relation with two attributes is in BCNF (D) BCNF is stronger than 3NF
by

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Answer :

(B) Lossless preserving decomposition into BCNF is always possible
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Consider a schema R(MNPQ) and functional dependencies M→N, P→Q. Then the decomposition of R into R1(MN) and R2(PQ) is ............. (1) Dependency preserving but not lossless join. (2) Dependency preserving and lossless join (3) Lossless join but not dependency preserving (4) Neither dependency preserving nor lossless join.

Description : Consider a schema R(MNPQ) and functional dependencies M→N, P→Q. Then the decomposition of R into R1(MN) and R2(PQ) is ............. (1) Dependency preserving but not lossless ... and lossless join (3) Lossless join but not dependency preserving (4) Neither dependency preserving nor lossless join. 

Last Answer : Answer: 1

A B C is a set of attributes. The functional dependency is as follows AB -> B AC -> C C -> B a) is in 1NF b) is in 2NF c) is in 3NF d) is in BCNF

Description : A B C is a set of attributes. The functional dependency is as follows AB -> B AC -> C C -> B a) is in 1NF b) is in 2NF c) is in 3NF d) is in BCNF

Last Answer : a) is in 1NF

Which of the following statements is TRUE? D1: The decomposition of the schema R(A,B,C) into R1(A,B) and R2(A,C) is always lossless. D2: The decomposition of the schema R(A,B,C,D,E) having AD→B, C→DE, B→AE, AE→C into R1(A,B,D) and R2(A,C,D,E) is lossless. (A) Both D1 and D2 (B) Neither D1 and D2 (C) Only D1 (D) Only D2

Description : Which of the following statements is TRUE? D1: The decomposition of the schema R(A,B,C) into R1(A,B) and R2(A,C) is always lossless. D2: The decomposition of the schema R(A,B,C,D,E) having AD→B, C→DE, B→AE, AE→C ... ,D,E) is lossless. (A) Both D1 and D2 (B) Neither D1 and D2 (C) Only D1 (D) Only D2

Last Answer : (D) Only D2

The relation schemas R1 and R2 form a Lossless join decomposition of R if and only if: (a) R1⋂R2→(R1-R2) (b) R1→R2 (c) R1⋂R2→(R2-R1) (d) R2→R1⋂R2 (A) (a) and (b) happens (B) (a) and (d) happens (C) (a) and (c) happens (D) (b) and (c) happens

Description : The relation schemas R1 and R2 form a Lossless join decomposition of R if and only if: (a) R1⋂R2→(R1-R2) (b) R1→R2 (c) R1⋂R2→(R2-R1) (d) R2→R1⋂R2 (A) (a) and (b) happens (B) (a) and (d) happens (C) (a) and (c) happens (D) (b) and (c) happens

Last Answer : (C) (a) and (c) happens 

Select operator is not a unary operator. ii) Project operator chooses subset of attributes or columns of a relation. A) i-True, ii-False B) i-True, ii-True C) i-False, ii-True D) i-False, ii-False

Description : Select operator is not a unary operator. ii) Project operator chooses subset of attributes or columns of a relation. A) i-True, ii-False B) i-True, ii-True C) i-False, ii-True D) i-False, ii-False

Last Answer : C) i-False, ii-True

For a database relation R(a, b, c, d) where the domains of a, b, c, d include only the atomic values. The functional dependency a → c, b → d holds in the following relation (A) In 1NF not in 2NF (B) In 2NF not in 3NF (C) In 3NF (D) In 1NF

Description : For a database relation R(a, b, c, d) where the domains of a, b, c, d include only the atomic values. The functional dependency a → c, b → d holds in the following relation (A) In 1NF not in 2NF (B) In 2NF not in 3NF (C) In 3NF (D) In 1NF

Last Answer : (A) In 1NF not in 2NF 

Which normal form is considered as adequate for usual database design? (A) 2NF (B) 3NF (C) 4NF (D) 5NF

Description : Which normal form is considered as adequate for usual database design? (A) 2NF (B) 3NF (C) 4NF (D) 5NF

Last Answer : (B) 3NF

Which of the following statements is FALSE about weak entity set ? (A) Weak entities can be deleted automatically when their strong entity is deleted. (B) Weak entity set avoids the data duplication and consequent possible inconsistencies caused by duplicating the key of the strong entity. (C) A weak entity set has no primary keys unless attributes of the strong entity set on which it depends are included. (D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Description : Which of the following statements is FALSE about weak entity set ? (A) Weak entities can be deleted automatically when their strong entity is deleted. (B) Weak entity set avoids the data ... weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Last Answer : (D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

A .................. normal form normalization will be needed where all attributes in a relation tuple are not functionally dependent only on the key attribute. A) First B) Second C) Third D) Fourth

Description : A .................. normal form normalization will be needed where all attributes in a relation tuple are not functionally dependent only on the key attribute. A) First B) Second C) Third D) Fourth

Last Answer : C) Third

If an attribute of a composite key is dependent on an attribute of the other composite key, a normalization called ................ is needed. A) DKNF B) BCNF C) Fourth D) Third

Description : If an attribute of a composite key is dependent on an attribute of the other composite key, a normalization called ................ is needed. A) DKNF B) BCNF C) Fourth D) Third

Last Answer : B) BCNF

………………….. operator is basically a join followed by a project on the attributes of first relation. A) Join B) Semi-Join C) Full Join D) Inner Join

Description : ………………….. operator is basically a join followed by a project on the attributes of first relation. A) Join B) Semi-Join C) Full Join D) Inner Join

Last Answer : B) Semi-Join

The number of attributes in relation is called as its ..................... A) Cardinality B) Degree C) Tuples D) Entity

Description : The number of attributes in relation is called as its ..................... A) Cardinality B) Degree C) Tuples D) Entity

Last Answer : B) Degree

The number of tuples in a relation is called its …………. While the number of attributes in a relation is called it’s ……………….. A) Degree, Cardinality B) Cardinality, Degree C) Rows, Columns

Description : The number of tuples in a relation is called its …………. While the number of attributes in a relation is called it’s ……………….. A) Degree, Cardinality B) Cardinality, Degree C) Rows, Columns

Last Answer : B) Cardinality, Degree

_____ produces the relation that has attributes of R1 and R2 (A) Cartesian product (B) Difference (C) Intersection (D) Product

Description : _____ produces the relation that has attributes of R1 and R2 (A) Cartesian product (B) Difference (C) Intersection (D) Product

Last Answer : A) Cartesian product

Consider a database table R with attributes A and B. Which of the following SQL queries is illegal ? (A) SELECT A FROM R; (B) SELECT A, COUNT(*) FROM R; (C) SELECT A, COUNT(*) FROM R GROUP BY A; (D) SELECT A, B, COUNT(*) FROM R GROUP BY A, B;

Description : Consider a database table R with attributes A and B. Which of the following SQL queries is illegal ? (A) SELECT A FROM R; (B) SELECT A, COUNT(*) FROM R; (C) SELECT A, COUNT(*) FROM R GROUP BY A; (D) SELECT A, B, COUNT(*) FROM R GROUP BY A, B;

Last Answer : (B) SELECT A, COUNT(*) FROM R;

In the ........... normal form, a composite attribute is converted to individual attributes. A) First B) Second C) Third D) Fourth

Description : In the ........... normal form, a composite attribute is converted to individual attributes. A) First B) Second C) Third D) Fourth

Last Answer : A) First

The main task carried out in the …………… is to remove repeating attributes to separate tables. A) First Normal Form B) Second Normal Form C) Third Normal Form D) Fourth Normal Form

Description : The main task carried out in the …………… is to remove repeating attributes to separate tables. A) First Normal Form B) Second Normal Form C) Third Normal Form D) Fourth Normal Form

Last Answer : D) Fourth Normal Form

What is BCNF (Boyce-Codd Normal Form)?

Description : What is BCNF (Boyce-Codd Normal Form)?

Last Answer : A relation schema R is in BCNF if it is in 3NF and satisfies an additional constraint that for every FD X A, X must be a candidate key.

Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table: Image I: {B} II: {B, C} III: {A, D} IV: {C, D} If different symbols stand for different values in the table (e.g., d1 is definitely not equal to d2), then which of the above could not be the candidate key for the database table? (A) I and III only (B) III and IV only (C) II only (D) I only

Description : Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table: I: {B} II: {B, C} III: {A, D} IV: {C, D} If ... the database table? (A) I and III only (B) III and IV only (C) II only (D) I only

Last Answer : (C) II only

Suppose ORACLE relation R(A, B) currently has tuples {(1, 2), (1, 3), (3, 4)} and relation S(B, C) currently has {(2, 5), (4, 6), (7, 8)}. Consider the following two SQL queries SQ1 and SQ2 : SQ1 : Select * From R Full Join S On R.B=S.B; SQ2 : Select * From R Inner Join S On R.B=S.B; The numbers of tuples in the result of the SQL query SQ1 and the SQL query SQ2 are given by : (A) 2 and 6 respectively (B) 6 and 2 respectively (C) 2 and 4 respectively (D) 4 and 2 respectively

Description : Suppose ORACLE relation R(A, B) currently has tuples {(1, 2), (1, 3), (3, 4)} and relation S(B, C) currently has {(2, 5), (4, 6), (7, 8)}. Consider the following two SQL queries SQ1 and SQ2 ... (A) 2 and 6 respectively (B) 6 and 2 respectively (C) 2 and 4 respectively (D) 4 and 2 respectively

Last Answer : (D) 4 and 2 respectively

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 are: A→C B→D The relation R is in ................ (1) First normal form but not in second normal form (2) Both in first normal form as well as in second normal form (3) Second normal form but not in third normal form (4) Both in second normal form as well as in third normal form

Description : 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 are: A→C B→D The ... form but not in third normal form (4) Both in second normal form as well as in third normal form

Last Answer : First normal form but not in second normal form

The rate of ……………. Is always an important factor for management especially in relation to the rate of return A) Cost B) Benefit C) Sales D) Investment

Description : The rate of ……………. Is always an important factor for management especially in relation to the rate of return A) Cost B) Benefit C) Sales D) Investment

Last Answer : D) Investment

Consider the following two commands C1 and C2 on the relation R from an SQL database: C1: drop table R; C2: delete from R; Which of the following statements is TRUE? I. Both C1 and C2 delete the schema for R. II. C2 retains relation R, but deletes all tuples in R. III. C1 deletes not only all tuples of R, but also the schema for R. (A) I only (B) I and II only (C) II and III only (D) I, II and III

Description : Consider the following two commands C1 and C2 on the relation R from an SQL database:  C1: drop table R; C2: delete from R; Which of the following statements is TRUE? I. Both C1 and C2 delete the schema for R. II. C2 ... R. (A) I only (B) I and II only (C) II and III only (D) I, II and III

Last Answer : (C) II and III only

What kind of mechanism is to be taken into account for converting a weak entity set into strong entity set in entity-relationship diagram ? (A) Generalization (B) Aggregation (C) Specialization (D) Adding suitable attributes

Description : What kind of mechanism is to be taken into account for converting a weak entity set into strong entity set in entity-relationship diagram ? (A) Generalization (B) Aggregation (C) Specialization (D) Adding suitable attributes

Last Answer : (D) Adding suitable attributes

A thread is usually defined as a light weight process because an Operating System (OS) maintains smaller data structure for a thread than for a process. In relation to this, which of the following statement is correct? (A) OS maintains only scheduling and accounting information for each thread. (B) OS maintains only CPU registers for each thread. (C) OS does not maintain a separate stack for each thread. (D) OS does not maintain virtual memory state for each thread.

Description : A thread is usually defined as a light weight process because an Operating System (OS) maintains smaller data structure for a thread than for a process. In relation to this, which of the following ... separate stack for each thread. (D) OS does not maintain virtual memory state for each thread.

Last Answer : (B) OS maintains only CPU registers for each thread.

Which of the following commands is used to display the directory attributes rather than its contents? A. ls -l -d B. ls -l C. ls -x D. ls -F E. None of the above

Description : Which of the following commands is used to display the directory attributes rather than its contents? A. ls -l -d B. ls -l C. ls -x D. ls -F E. None of the above

Last Answer : A. ls -l -d

............. is a combination of two of more attributes used as a primary key A) Composite Key B) Alternate Key C) Candidate Key D) Foreign Key

Description : ............. is a combination of two of more attributes used as a primary key A) Composite Key B) Alternate Key C) Candidate Key D) Foreign Key

Last Answer : A) Composite Key

Let E1 and E2 be two entities in E-R diagram with simple single valued attributes. R1 and R2 are two relationships between E1 and E2 where R1 is one-many and R2 is many-many. R1 and R2 do not have any attributes of their own. How many minimum number of tables are required to represent this situation in the Relational Model? (A) 4 (B) 3 (C) 2 (D) 1

Description : Let E1 and E2 be two entities in E-R diagram with simple single valued attributes. R1 and R2 are two relationships between E1 and E2 where R1 is one-many and R2 is many-many. R1 and R2 do not have any ... are required to represent this situation in the Relational Model? (A) 4 (B) 3 (C) 2 (D) 1

Last Answer : (B) 3 

Let M and N be two entities in an E-R diagram with simple single vale attributes. R1 and R2 are two relationship between M and N, whereas R1 is one-to-many and R2 is many-to-many. The minimum number of tables required to represent M, N, R1 and R2 in the relational model are .......... (1) 4 (2) 6 (3) 7 (4) 3

Description : Let M and N be two entities in an E-R diagram with simple single vale attributes. R1 and R2 are two relationship between M and N, whereas R1 is one-to-many and R2 is many-to-many. The minimum number of tables required to ... and R2 in the relational model are .......... (1) 4 (2) 6 (3) 7 (4) 3

Last Answer : Answer: 4

Identify the criteria for designing database from the point of view of user A) No redundancy B) No inapplicable attributes C) Uniformity in naming & definitions of the data items D) All of the above

Description : Identify the criteria for designing database from the point of view of user A) No redundancy B) No inapplicable attributes C) Uniformity in naming & definitions of the data items D) All of the above

Last Answer : D) All of the above

In RDBMS, Data is presented as a collection of ............ A) Table B) Attributes C) Relations D) Entities

Description : In RDBMS, Data is presented as a collection of ............ A) Table B) Attributes C) Relations D) Entities

Last Answer : C) Relations

A ………………. Does not have a distinguishing attribute if its own and mostly are dependent entities, which are part of some another entity. A) Weak entity B) Strong entity C) Non attributes entity D) Dependent entity

Description : A ………………. Does not have a distinguishing attribute if its own and mostly are dependent entities, which are part of some another entity. A) Weak entity B) Strong entity C) Non attributes entity D) Dependent entity

Last Answer : A) Weak entity

The one guideline to be followed while designing the database is A) A database design may be ambiguous. B) Unrelated data should be in the same table so that updating the data will be easy. C) It should avoid/reduce the redundancy. D) An entity should not have attributes.

Description : The one guideline to be followed while designing the database is A) A database design may be ambiguous. B) Unrelated data should be in the same table so that updating the data will be easy. C) It should avoid/reduce the redundancy. D) An entity should not have attributes.

Last Answer : C) It should avoid/reduce the redundancy.

In a relational model, relations are termed as (A) Tuples. (B) Attributes (C) Tables. (D) Rows.

Description : In a relational model, relations are termed as (A) Tuples. (B) Attributes (C) Tables. (D) Rows.

Last Answer : (C) Tables

In the relational modes, cardinality is termed as: (A) Number of tuples. (B) Number of attributes. (C) Number of tables. (D) Number of constraints

Description : In the relational modes, cardinality is termed as: (A) Number of tuples. (B) Number of attributes. (C) Number of tables. (D) Number of constraints

Last Answer : (A) Number of tuples

An ER Model includes I. An ER diagram portraying entity types. II. Attributes for each entity type III. Relationships among entity types. IV. Semantic integrity constraints that reflects the business rules about data not captured in the ER diagram. (A) I, II, III & IV (B) I&IV (C) I, II & IV (D) I & III

Description : An ER Model includes I. An ER diagram portraying entity types. II. Attributes for each entity type III. Relationships among entity types. IV. Semantic integrity constraints that reflects the business rules about data not ... ; IV (B) I&IV (C) I, II & IV (D) I & III

Last Answer : (A) I, II, III & IV

Which one of the following set of attributes should not be encompassed by effective software metrics ? (A) Simple and computable (B) Consistent and objective (C) Consistent in the use of units and dimensions (D) Programming language dependent

Description : Which one of the following set of attributes should not be encompassed by effective software metrics ? (A) Simple and computable (B) Consistent and objective (C) Consistent in the use of units and dimensions (D) Programming language dependent

Last Answer : (D) Programming language dependent

Which one of the following non-functional quality attributes is not highly affected by the architecture of the software ? (A) Performance (B) Reliability (C) Usability (D) Portability

Description : Which one of the following non-functional quality attributes is not highly affected by the architecture of the software ? (A) Performance (B) Reliability (C) Usability (D) Portability

Last Answer : (C) Usability

Semi-join strategies are techniques for query processing in distributed database system. Which of the following is a semi-join technique? (A) Only the joining attributes are sent from one site to another and then all of the rows are returned. (B) All of the attributes are sent from one site to another and then only the required rows are returned. (C) Only the joining attributes are sent from one site to another and then only the required rows are returned. (D) All of the attributes are sent from one site to another and then only the required rows are returned.

Description : Semi-join strategies are techniques for query processing in distributed database system. Which of the following is a semi-join technique? (A) Only the joining attributes are sent from one site to ... the attributes are sent from one site to another and then only the required rows are returned.

Last Answer : (C) Only the joining attributes are sent from one site to another and then only the required rows are returned.

Which layer of OSI reference model is responsible for decomposition of messages and generation of sequence numbers to ensure correct re-composition from end to end of the network? (A) Physical (B) Data-link (C) Transport (D) Application

Description : Which layer of OSI reference model is responsible for decomposition of messages and generation of sequence numbers to ensure correct re-composition from end to end of the network? (A) Physical (B) Data-link (C) Transport (D) Application

Last Answer : (C) Transport 

Which of the following statements is false about the acid-strength of acetic acid? (a) Acetic acid is a stronger acid than monochloroacetic acid(b) Acetic acid is a stronger acid than propionic acid. (c) Acetic acid is a weaker acid than trichloroacetic acid. (d) Acetic acid is a weaker acid than formic acid.

Description : Which of the following statements is false about the acid-strength of acetic acid? (a) Acetic acid is a stronger acid than monochloroacetic acid. (b) Acetic acid is a stronger acid than propionic acid. ... is a weaker acid than trichloroacetic acid. (d) Acetic acid is a weaker acid than formic acid

Last Answer : Acetic acid is a stronger acid than monochloroacetic acid

Consider the following two statements : (a) Data scrubling is a process to upgrade the quality of data, before it is moved into Data warehouse. (b) Data scrubling is a process of rejecting data from data warehouse to create indexes. Which one of the following options is correct ? (A) (a) is true, (b) is false (B) (a) is false, (b) is true (C) Both (a) and (b) are false (D) Both (a) and (b) are true

Description : Consider the following two statements : (a) Data scrubling is a process to upgrade the quality of data, before it is moved into Data warehouse. (b) Data scrubling is a process of rejecting data from data warehouse to create ... true (C) Both (a) and (b) are false (D) Both (a) and (b) are true

Last Answer : (A) (a) is true, (b) is false

An inference algorithm that derives only entailed sentences is called sound or truth-preserving. a) True b) False

Description : An inference algorithm that derives only entailed sentences is called sound or truth-preserving. a) True b) False

Last Answer : a) True

An Assertion is a predicate expressing a condition we wish database to always satisfy. The correct syntax for Assertion is : (A) CREATE ASSERTION ‘ASSERTION Name’ CHECK ‘Predicate’ (B) CREATE ASSERTION ‘ASSERTION NAME’ (C) CREATE ASSERTION, CHECK Predicate (D) SELECT ASSERTION

Description : An Assertion is a predicate expressing a condition we wish database to always satisfy. The correct syntax for Assertion is : (A) CREATE ASSERTION ‘ASSERTION Name’ CHECK ‘Predicate’ (B) CREATE ASSERTION ‘ASSERTION NAME’ (C) CREATE ASSERTION, CHECK Predicate (D) SELECT ASSERTION

Last Answer : (A) CREATE ASSERTION ‘ASSERTION Name’ CHECK ‘Predicate’ 

What is 3NF?

Description : What is 3NF?

Last Answer : A relation schema R is in 3NF if it is in 2NF and for every FD X A either of the following is true ∙ X is a Super-key of R. ∙ A is a prime attribute of R. In other wo