Er Diagrams · Database Management System · GATE CSE

Marks 1

In the context of owner and weak entity sets in the ER (Entity-Relationship) data model, which one of the following statements is TRUE?

GATE CSE 2024 Set 2

Let S be the specification : "Instructors teach courses. Students register for courses. Courses are allocated classrooms. Instructors guide students." Which one of the following ER diagrams CORRECTLY represents S?

GATE CSE 2024 Set 1

Which one of the options given below refers to the degree (or arity) of a relation in relational database systems?

GATE CSE 2023

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

GATE CSE 2020

Which of the following is NOT a superkey in a relational schema with attributes $$V, W, X, Y, Z$$ and primary key $$V Y?$$

GATE CSE 2016 Set 1

Given an instance of the STUDENTS relation as shown below:

For (StudentName, StudentAge) to be a key for this instance, the value $$X$$ should NOT be equal to ________.

GATE CSE 2014 Set 2

An index is clustered, if

GATE CSE 2013

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

GATE CSE 2012

Consider a relation table with a single record for each registered student with a single record for each registered student with the following attributes.
$$1.$$ $$Registration$$ $$Num:$$ Unique registration number of each registered student.
$$2.$$ $$UID :$$ Unique identity number, unique at the national level for each cityzen.
$$3.$$ $$BankAccount_Num:$$ Unique account number at the bank. A student can have multiple accounts or joint accounts. This attribute stores the primary account number.
$$4.$$ $$Name:$$ Name of the student
$$5.$$ $$Hostel$$ $$Room:$$ Room number of the hostel.

Which of the following options is INCORRECT?

GATE CSE 2011

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

GATE CSE 2005

Marks 2

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 $$R$$?

GATE CSE 2018

Consider the following $$ER$$ diagram

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

GATE CSE 2008

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?

GATE CSE 2008

Let $${E_1}$$ and $${E_2}$$ be two entities in an E-R diagram with simple single-valued attributes, $${E_1}$$ and $${E_2}$$ are two relationships between $${E_1}$$ and $${E_2}$$, Where $${E_1}$$ is one-to-many and $${E_2}$$ is many-to-many. $${E_1}$$ and $${E_2}$$ do not have any attributes of their own. What is the minimum number of tables required represent this situation in the relation model?

GATE CSE 2005

The following table has two attributes $$A$$ and $$C$$ where $$A$$ is the primary key and $$C$$ is the foreign key referencing $$A$$ with on-delete cascade.

The set of all tuples that must be additionally deleted to preserve referential integrity. When the tuple $$(2,4)$$ is deleted is:

GATE CSE 2005

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 form the above $$ERD.$$ The minimum number of tables in the database is

GATE CSE 2004