Which one of the following is used to represent the supporting many-one relationships of a weak entity set in an entity-relationship diagram?

Given the basic ER and relational models, which of the following is INCORRECT?

Consider the following entity relationship diagram (ERD), where two entities E1 and E2 have a relation R of cardinality 1 : m.

The attributes of E1 are A11, A12 and A13 where A11 is the key attribute. The attributes of E2 are A21, A22 and A23 where A21 is the key attribute and A23 is a multi-valued attribute. Relation R does not have any attribute. A relational database containing minimum number of tables with each table satisfying the requirements of the third normal form (3NF) is designed from the above ERD. The number of tables in the database is

Consider two tables in a relational database with columns and rows as follows:

Table: Student
ROLL_NO	  NAME	DEPT_ID
   1	  ABC	   1
   2	  DEF	   1
   3	  GHI	   2
   4	  JKL	   3
Table: Department
DEPT_ID	DEPT_NAME
   1	   A
   2	   B
   3	   C 

(i)  update Student set Dept_id = Null 
     where Roll_on = 1
(ii) update Department set Dept_id = Null 
     where Dept_id = 1 

Consider the entities 'hotel room', and 'person' with a many to many relationship 'lodging' as shown below:

If we wish to store information about the rent payment to be made by person (s) occupying different hotel rooms, then this information should appear as an attribute of

In a schema with attributes A, B, C, D and E following set of functional dependencies are given

A → B 
A → C 
CD → E 
B → D 
E → A 

What is the optimized version of the relation algebra expression π_A1(π_A2(σ_F1(σ_F2(r)))), where A1, A2 are sets of attributes in  with A1 ⊂ A2 and F1, F2 are Boolean expressions based on the attributes in r?

A prime attribute of a relation scheme is an attribute that appears

Consider the relational schema given below, where eId of the relation dependent is a foreign key referring to empId of the relation employee. Assume that every employee has at least one associated dependent in the dependent relation.

employee (empId, empName, empAge)
dependent(depId, eId, depName, depAge)

Consider the following relational algebra query:

∏empId(employee)-∏empId(employee⋈(empId = eID)∧(empAge ≤ depAge)dependent)

The above query evaluates to the set of empIds of employees whose age is greater than that of

Consider an Entity-Relationship (ER) model in which entity sets E₁ and E₂ are connected by an m:n relationship R₁₂, E₁ and E₃ are connected by a 1:n (1 on the side of E₁ and n on the side of E₃) relationship R₁₃.

E₁ has two single-valued attributes a₁₁ and a₁₂ of which a₁₁ is the key attribute. E₂ has two single-valued attributes a₂₁ and a₂₂ is the key attribute. E₃ has two single-valued attributes a₃₁ and a₃₂ of which a₃₁ is the key attribute. The relationships do not have any attributes.

If a relational model is derived from the above ER model, then the minimum number of relations that would be generated if all the relations are in 3NF is ___________.

An ER model of a database consists of entity types A and B. These are connected by a relationship R which does not have its own attribute. Under which one of the following conditions, can the relational table for R be merged with that of A?

In an Entity-Relationship (ER) model, suppose R is a many-to-one relationship from entity set E1 to entity set E2. Assume that E1 and E2 participate totally in R and that the cardinality of E1 is greater than the cardinality of E2.

Which one of the following is true about R?

Consider the following ER diagram

The minimum number of tables needed to represent M, N, P, R1, R2 is

Consider the following ER diagram

Which of the following is a correct attribute set for one of the tables for the correct answer to the above question?

Let E₁ and E₂ be two entities in an E/R diagram with simple single-valued attributes. R₁ and R₂ are two relationships between E₁ and E₂, where R₁ is one-to-many and R₂ is many-to-many. R₁ and R₂ do not have any attributes of their own. What is the minimum number of tables required to represent this situation in the relational model?

Consider the following relation schema

Students(rollno: integer, sname: string)
Courses(courseno: integer, cname: string)
Registration(rollno: integer, courseno: integer, percent: real)

Which of the following queries are equivalent to this query in English?

"Find the distinct names of all students who score more than 90% in the course numbered 107" 

(I) SELECT DISTINCT S.sname
    FROM Students as S,Registration as R
    WHERE R.rollno = S.roll AND R.courseno = 107 AND R.percent > 90
(II) Πsname(σcourseno=107∧percent>90(Registration ⋈ Students))
(III) {T|∃S ∈ Students, ∃R ∈ Registration (S.rollno = R.rollno ∧ R.courseno = 107 ∧ R.percent > 90 ∧ T.sname = S.sname)}
(IV) {〈SN〉|∃SR∃RP(〈SR,SN〉 ∈ Students ∧ 〈SR,107,RP〉 ∈ Registration ∧ RP>90)}