Recent questions tagged er-diagram / GATE Overflow for GATE CSE

Construct an E-R diagram for a hospital with a set of patients and a set ofmedical doctors. Associate with each patient a log of the various tests andexaminations conduct...

ajaysoni1924

738 views

ajaysoni1924 asked Mar 28, 2019

2 votes

2 answers

64

DBMS Korth Edition 6 Exercise 7 Question 14 (Page No. 318)
Explain the distinctions among the terms primary key, candidate key, and superkey.

Explain the distinctions among the terms primary key, candidate key, andsuperkey.

ajaysoni1924

1.6k views

ajaysoni1924 asked Mar 28, 2019

2 votes

1 answer

65

DBMS Korth Edition 6 Exercise 7 Question 13 (Page No. 318)
Temporal changes: An E-R diagram usually models the state of an enterprise at a point in time. Suppose we wish to track temporal changes, that is, changes to data over time. For example, Zhang may have been a student between ... , with the above extensions to track temporal changes. b. Convert the above E-R diagram into a set of relations.

Temporal changes: An E-R diagram usually models the state of an enterpriseat a point in time. Suppose we wish to track temporal changes, that is,changes to data over time...

ajaysoni1924

631 views

ajaysoni1924 asked Mar 28, 2019

1 votes

0 answers

66

DBMS Korth Edition 6 Exercise 7 Question 12 (Page No. 317-318)
Figure shows a lattice structure of generalization and specialization (attributes not shown). For entity sets A, B, and C, explain how attributes are inherited from the higher-level entity sets X and Y. Discuss how to handle a case where an attribute of X has the same name as some attribute of Y.

Figure shows a lattice structure of generalization and specialization(attributes not shown). For entity sets A, B, and C, explain how attributes are inherited from the hi...

ajaysoni1924

546 views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

67

DBMS Korth Edition 6 Exercise 7 Question 11 (Page No. 317)
In SQL, foreign key constraints can only reference the primary key attributes of the referenced relation, or other attributes declared to be a super key using the unique constraint. As a result, total participation constraints on a ... 4.4.7 of korth). (Unfortunately, these features are not supported on any widely used database currently.)

In SQL, foreign key constraints can only reference the primary key attributesof the referenced relation, or other attributes declared to be a super key usingthe unique co...

ajaysoni1924

769 views

ajaysoni1924 asked Mar 28, 2019

4 votes

0 answers

68

DBMS Korth Edition 6 Exercise 7 Question 10 (Page No. 317)
Consider a many-to-one relationship R between entity sets A and B. Suppose the relation created from R is combined with the relation created from A. In SQL, attributes participating in a foreign key constraint can be null. Explain how a constraint on total participation of A in R can be enforced using not null constraints in SQL.

Consider a many-to-one relationship R between entity sets A and B. Supposethe relation created from R is combined with the relation created fromA. In SQL, attributes part...

ajaysoni1924

673 views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

69

DBMS Korth Edition 6 Exercise 7 Question 9 (Page No. 317)
Suppose the advisor relationship was one-to-one. What extra constraints are required on the relation advisor to ensure that the one-to-one cardinality constraint is enforced?

Suppose the advisor relationship was one-to-one. What extra constraintsare required on the relation advisor to ensure that the one-to-one cardinalityconstraint is enforce...

ajaysoni1924

322 views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

70

DBMS Korth Edition 6 Exercise 7 Question 8 (Page No. 317)
Consider a relation such as sec_course, generated from a many-to-one relationship sec_course. Do the primary and foreign key constraints created on the relation enforce the many-to-one cardinality constraint? Explain why.

Consider a relation such as sec_course, generated from a many-to-one relationshipsec_course. Do the primary and foreign key constraints created onthe relation enforce the...

ajaysoni1924

284 views

ajaysoni1924 asked Mar 28, 2019

2 votes

0 answers

71

DBMS Korth Edition 6 Exercise 7 Question 7 (Page No. 317)
A weak entity set can always be made into a strong entity set by adding to its attributes the primary-key attributes of its identifying entity set. Outline what sort of redundancy will result if we do so.

A weak entity set can always be made into a strong entity set by adding toits attributes the primary-key attributes of its identifying entity set. Outlinewhat sort of red...

ajaysoni1924

1.1k views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

72

DBMS Korth Edition 6 Exercise 7 Question 6 (Page No. 316-317)
Consider the representation of a ternary relationship using binary relationships as described in this book and illustrated in Figure (b) (attributes not shown) a. Show a simple instance of E, A, B,C, RA, RB, and RC that cannot correspond ... for E. Show how to treat E as a weak entity set so that a primary-key attribute is not required.

Consider the representation of a ternary relationship using binary relationshipsas described in this book and illustrated in Figure (b) (attributesnot shown)a. Show a sim...

ajaysoni1924

581 views

ajaysoni1924 asked Mar 28, 2019

1 votes

0 answers

73

DBMS Korth Edition 6 Exercise 7 Question 5 (Page No. 316)
An E-R diagram can be viewed as a graph. What do the following mean in terms of the structure of an enterprise schema? a. The graph is disconnected. b. The graph has a cycle.

An E-R diagram can be viewed as a graph. What do the following mean interms of the structure of an enterprise schema?a. The graph is disconnected.b. The graph has a cycle...

ajaysoni1924

570 views

ajaysoni1924 asked Mar 28, 2019

1 votes

0 answers

74

DBMS Korth Edition 6 Exercise 7 Question 4 (Page No. 316)
Consider an E-R diagram in which the same entity set appears several times, with its attributes repeated in more than one occurrence. Why is allowing this redundancy a bad practice that one should avoid?

Consider an E-R diagram in which the same entity set appears several times,with its attributes repeated in more than one occurrence. Why is allowingthis redundancy a bad...

ajaysoni1924

387 views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

75

DBMS Korth Edition 6 Exercise 7 Question 3,17 (Page No. 316-319)
Design an E-R diagram for keeping track of the exploits of your favorite sports team. You should store the matches played, the scores in each match, the players in each match, and individual player statistics for each match. ... . b)Extend the E-R diagram of above exercise to track the same information for all teams in a league.

Design an E-R diagram for keeping track of the exploits of your favoritesports team. You should store the matches played, the scores in each match,the players in each mat...

ajaysoni1924

944 views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

76

DBMS Korth Edition 6 Exercise 7 Question 2 (Page No. 315)
Consider a database used to record the marks that students get in different exams of different course offerings (sections). a. Construct an E-R diagram that models exams as entities, and uses a ternary relationship, for the ... a particular student and section pair, yet you can represent the marks that a student gets in different exams.

Consider a database used to record the marks that students get in differentexams of different course offerings (sections).a. Construct an E-R diagram that models exams as...

ajaysoni1924

375 views

ajaysoni1924 asked Mar 28, 2019

0 votes

0 answers

77

DBMS Korth Edition 6 Exercise 7 Question 1 (Page No. 316)
Construct an E-R diagram for a car insurance company whose customers own one or more cars each. Each car has associated with it zero to any number of recorded accidents. Each insurance policy covers one or more cars and has one ... is for a particular period of time and has an associated due date, and the date when the payment was received.

Construct an E-R diagram for a car insurance company whose customersown one or more cars each. Each car has associated with it zero to anynumber of recorded accidents. Ea...

ajaysoni1924

702 views

ajaysoni1924 asked Mar 28, 2019

0 votes

1 answer

78

RDMS table
How many minimum Relations required from the following ER Diagram which are satisfy 4 NF?

How many minimum Relations required from the following ER Diagram which are satisfy 4 NF?

s_dr_13

466 views

s_dr_13 asked Mar 6, 2019

0 votes

1 answer

79

#DBMS
What are the parameters or procedure to follow to find out minimum no. of tables for given ER Diagram type of questions?

What are the parameters or procedure to follow to find out minimum no. of tables for given ER Diagram type of questions?

Reshu $ingh

412 views

Reshu $ingh asked Jan 28, 2019

0 votes

0 answers

80

applied course
How to convert above E-R diagram to Relations? Sorry for adding image instead of typing..

How to convert above E-R diagram to Relations?Sorry for adding image instead of typing..

screddy1313

575 views

screddy1313 asked Jan 27, 2019

4 votes

0 answers

81

MadeEasy Full Length Test 2019: Databases - Er Diagram
Find minimum number of tables needed? Answer : (3) Can anyone please explain the answer and how to approach such complex er diagrams?

Find minimum number of tables needed?Answer : (3)Can anyone please explain the answer and how to approach such complex er diagrams?

vk_9_1_9

903 views

vk_9_1_9 asked Jan 26, 2019

3 votes

0 answers

82

MadeEasy Full Length Test 2019: Databases - Er Diagram
Consider the following ER diagram: How many number of relations are required for the above ER diagram? 2 3 5 1 Solution: My doubt is: Since $E_2$ isn't involved in total participation with $E_1$ so on merging we might get 2NF ... 2-NF violation. So by default which case is to be considered when normalization form is not mentioned?? 1-NF?

Consider the following ER diagram:How many number of relations are required for the above ER diagram?2351Solution:My doubt is:Since $E_2$ isn’t involved in total partic...

MiNiPanda

786 views

MiNiPanda asked Jan 18, 2019

0 votes

1 answer

83

Confused
In ER-DIAGRAM to Relation conversion : I can't understand how to handle the following points How to deal with one-to-one relationship with any of the entity having total participation in relation? How to deal with One-to-many relationship with an entity ... in the relationship? How to deal with many-to-many relationship with total participation of one or both the entities in relation?

In ER-DIAGRAM to Relation conversion :I can’t understand how to handle the following pointsHow to deal with one-to-one relationship with any of the entity having total ...

Shivam Kasat

635 views

Shivam Kasat asked Jan 17, 2019

0 votes

2 answers

84

ER to relation
Answer has R4 and E2 merged, I cant visualize how? what will be primary key? What will be other attributes?

Answer has R4 and E2 merged, I cant visualize how? what will be primary key? What will be other attributes?

bts1jimin

581 views

bts1jimin asked Jan 16, 2019

2 votes

1 answer

85

ER Model (Applied Course Mock 3)
In ER model, which of the following is TRUE about weak entity Weak entity is not always existence dependent i.e., weak entity can exist without the entity with which it has a relationship Weak entity has a primary key that is partially or totally derived from the parent entity in a relationship Only I Only II Both I and II Neither I nor II

In ER model, which of the following is TRUE about weak entityWeak entity is not always existence dependent i.e., weak entity can exist without the entity with which it ha...

Mk Utkarsh

1.2k views

Mk Utkarsh asked Jan 14, 2019

0 votes

1 answer

86

Ace Test Series: DBMS - ER Diagram To Table

Çșȇ ʛấẗẻ

727 views

Çșȇ ʛấẗẻ asked Jan 14, 2019

1 votes

0 answers

87

MadeEasy Test Series 2019: Databases - Er Diagram
NO. OF RELATIONS REQURIED FOR THIS ER-DIAGRAM: I am getting answer 1, Reference :https://gateoverflow.in/201404/er-diagram read out @raviyogi comment

NO. OF RELATIONS REQURIED FOR THIS ER-DIAGRAM:I am getting answer 1,Reference :https://gateoverflow.in/201404/er-diagram read out @raviyogi comment

Shivam Kasat

637 views

Shivam Kasat asked Jan 13, 2019

1 votes

4 answers

88

MadeEasy Subject Test: Databases - Er Diagram
Minimum no of table for this ER diagram

Minimum no of table for this ER diagram

Gurdeep Saini

1.1k views

Gurdeep Saini asked Jan 6, 2019

3 votes

1 answer

89

MadeEasy Test Series: Databases - Er Diagram
Identify total number of attributes in minimized relation ?

Identify total number of attributes in minimized relation ?

Na462

674 views

Na462 asked Jan 6, 2019

0 votes

1 answer

90

UPPCL AE 2018:6
Let $\text{E}1$ and $\text{E}2$ be two entities in an $\text{E/R}$ diagram with simple single-valued attributes. $\text{R}1$ and $\text{R}2$ are two relationships between $\text{E}1$ and $\text{E}2,$ where $\text{R}1$ is one-to-many ... have any attributes of their own. What is the minimum number of tables required to represent this situation in the relational model? $2$ $4$ $3$ $5$

Let $\text{E}1$ and $\text{E}2$ be two entities in an $\text{E/R}$ diagram with simple single-valued attributes. $\text{R}1$ and $\text{R}2$ are two relationships between...

admin

326 views

admin asked Jan 5, 2019

tags	tag:apple
author	user:martin
title	title:apple
content	content:apple
exclude	-tag:apple
force match	+apple
views	views:100
score	score:10
answers	answers:2
is accepted	isaccepted:true
is closed	isclosed:true