Description : Which of the following statement is true? (1) A Primary key is also a candidate key (2) Each relation has at least one foreign key (3) Foreign keys can’t have null values (4) A Primary key is also an alternate key
Last Answer : Foreign keys can’t have null values
Description : An attribute that uniquely identifies the rows of a table is known as the ....... key. (1) primary (2) candidate (3) composite (4) foreign
Last Answer : primary
Description : The candidate key is that you choose to identify each row uniquely is called …………….. A) Alternet Key B) Primary Key C) Foreign Key D) None of the above
Last Answer : B) Primary Key
Description : Drop Table cannot be used to drop a table referenced by a …………… constraint. A) Local Key B) Primary Key C) Composite Key D) Foreign Key
Last Answer : D) Foreign Key
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
Description : Consider the following statements regarding relational database model: (a) NULL values can be used to opt a tuple out of enforcement of a foreign key. (b) Suppose that table T has only one candidate key. If Q is in 3NF, then it is ... true. (C) (b) and (c) are true. (D) (a), (b) and (c) are true.
Last Answer : (D) (a), (b) and (c) are true.
Description : Which one is correct w.r.t. RDBMS? (1) primary key ⊆ super key ⊆ candidate key (2) primary key ⊆ candidate key ⊆ super key (3) super key ⊆ candidate key ⊆ primary key (4) super key ⊆ primary key ⊆ candidate key
Last Answer : Answer: 2
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.
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
Description : ey to represent relationship between tables is called (A) Primary key (B) Secondary Key (C) Foreign Key (D) None of these
Last Answer : (C) Foreign Key
Description : Drop Table cannot be used to drop a Table referenced by .................. constraint. (a) Primary key (b) Sub key (c) Super key (d) Foreign key (A) (a) (B) (a), (b) and (c) (C) (d) (D) (a) and (d)
Last Answer : (C) (d)
Description : State true or false i) A candidate key is a minimal super key. ii) A candidate key can also refer to as surrogate key. A) i-true, ii-false B) i-false, ii-true C) i-true, ii-true D) i-false, ii-false
Last Answer : C) i-true, ii-true
Description : A relation R={A,B,C,D,E,F,G} is given with following set of functional dependencies: F={AD→E, BE→F, B→C, AF→G} Which of the following is a candidate key? (A) A (B) AB (C) ABC (D) ABD
Last Answer : Answer: D
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
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
Description : The Relation Vendor Order (V_no, V_ord_no, V_name, Qty_sup, unit_price) is in 2NF because : (A) Non key attribute V_name is dependent on V_no which is part of composite key (B) ... Qty_sup is dependent on primary_key unit price (D) key attribute V_ord_no is dependent on primary_key unit price
Last Answer : (A) Non key attribute V_name is dependent on V_no which is part of composite key
Description : Based on the cardinality ratio and participation ............... associated with a relationship type, choose either the Foreign Key Design, the Cross Referencing Design or Mutual Referencing Design. (A) Entity (B) Constraints (C) Rules (D) Keys
Last Answer : (B) Constraints
Description : The candidate key, which is not used as primary key is called ………….. key. -Technology
Last Answer : The candidate key, which is not used as primary key is calledalternate key.
Description : What is the difference between candidate key, unique key and primary key
Last Answer : Candidate keys are the columns in the table that could be the primary keys and the primary key is the key that has been selected to identify the rows. Unique key is also useful for identifying the distinct rows in the table.)
Description : Define primary key and candidate key.
Last Answer : Primary Key: A primary key is an attribute in Relation that uniquely identifies the rows in relation. A Primary key does not hold NULL values and duplicate values. OR A key which is selected by the ... , Name) can be a candidate key if and only if Name and Rollno individually are not unique.
Description : What is a composite primary key field ?
Last Answer : Answer : A combination of two or more attributes or keys can collectively identify an NTT set, but they are called composite primary keys.
Description : Consider the following relation: Works (emp_name, company_name, salary) Here, emp_name is primary key. Consider the following SQL query Select emp_name From Works T where salary>(select avg ( ... 4) Find all employees who earn more than the average salary of all employees of their company.
Last Answer : Find all employees who earn more than the average salary of all employees of their company.
Description : Consider the following database table : Create table test( one integer, two integer, primary key(one), unique(two), check(one≥1 and ≤10), check(two≥1 and ≤5) ); How many data records/tuples atmost can this table contain ? (A) 5 (B) 10 (C) 15 (D) 50
Last Answer : (A) 5
Description : Let pk(R) denotes primary key of relation R. A many-to-one relationship that exists between two relations R1 and R2 can be expressed as follows: (1) pk(R2)→pk(R1) (2) pk(R1)→pk(R2) (3) pk(R2)→R1∩R2 (4) pk(R1)→R1∩R2
Description : Integrity constraints ensure that changes made to the database by authorized users do not result into loss of data consistency. Which of the following statement(s) is (are) true w.r.t. the examples of integrity constraints? (A) An ... ) and (B) are true; (C) false. (4) (A), (B) and (C) are false.
Last Answer : Answer: 3
Description : In a relational database model, NULL values can be used for all but which one of the following? (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL. (B) To ... D) To fill a column in a tuple when that column does not really exist for that particular tuple.
Last Answer : (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL.
Description : Let R be the rectangular window against which the lines are to be clipped using 2D Sutherland-Cohen line clipping algorithm. The rectangular window has lower left-hand corner at (-5,1) and upper righthand corner at (3,7). ... s) is/are candidate for clipping? (A) AB (B) CD (C) EF (D) AB and CD
Last Answer : (D) AB and CD
Description : Which of the following special cases does not require reformulation of the problem in order to obtain a solution ? (A) Alternate optimality (B) Infeasibility (C) Unboundedness (D) All of the above
Last Answer : (A) Alternate optimality
Description : 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
Last Answer : (B) Lossless preserving decomposition into BCNF is always possible
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
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
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
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
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
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
Description : In RDBMS, Data is presented as a collection of ............ A) Table B) Attributes C) Relations D) Entities
Last Answer : C) Relations
Description : The number of attributes in relation is called as its ..................... A) Cardinality B) Degree C) Tuples D) Entity
Last Answer : B) Degree
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
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
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
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.
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
Description : In a relational model, relations are termed as (A) Tuples. (B) Attributes (C) Tables. (D) Rows.
Last Answer : (C) Tables
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
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
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
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
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
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.
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;