The document discusses database normalization and different normal forms including 1NF, 2NF, 3NF, and BCNF. It explains that normalization aims to reduce data redundancy and improve data integrity by creating tables where attributes depend on the primary key. Higher normal forms like BCNF are stronger than lower forms like 1NF. The concepts of functional dependencies, candidate keys, and normalizing relations are covered.
Normalization is a process that “improves” a database design by generating relations that are of higher normal forms.
The objective of normalization:
“to create relations where every dependency is on the key, the whole key, and nothing but the key”.
Normalization is the process of organizing data in a database. This includes creating tables and establishing relationships between those tables according to rules designed both to protect the data and to make the database more flexible by eliminating redundancy and inconsistent dependency.
Normalization is a process that “improves” a database design by generating relations that are of higher normal forms.
The objective of normalization:
“to create relations where every dependency is on the key, the whole key, and nothing but the key”.
Normalization is the process of organizing data in a database. This includes creating tables and establishing relationships between those tables according to rules designed both to protect the data and to make the database more flexible by eliminating redundancy and inconsistent dependency.
INTRODUCTION
3NF and BCNF
Decomposition requirements
Lossless join decomposition
Dependency preserving decomposition
Disk pack features
Records and Files
Ordered and Unordered files
2NF,NF,3NF,BCNF
INTRODUCTION
3NF and BCNF
Decomposition requirements
Lossless join decomposition
Dependency preserving decomposition
Disk pack features
Records and Files
Ordered and Unordered files
2NF,NF,3NF,BCNF
chapter 4-Functional Dependency and Normilization.pdfMisganawAbeje1
This chapter describe about the theory that has been developed with the goal of evaluating relational schemas for design quality , that is, to measure formally why one set of groupings of attributes into relation schemas is better than
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Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
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Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
1. Normalization
91.2914 1
Normalization
We discuss four normal forms: first, second, third, and
Boyce-Codd normal forms
1NF, 2NF, 3NF, and BCNF
Normalization is a process that “improves” a database
design by generating relations that are of higher normal
forms.
The objective of normalization:
“to create relations where every dependency is on the key,
the whole key, and nothing but the key”.
2. Normalization
91.2914 2
There is a sequence to normal forms:
1NF is considered the weakest,
2NF is stronger than 1NF,
3NF is stronger than 2NF, and
BCNF is considered the strongest
Also,
any relation that is in BCNF, is in 3NF;
any relation in 3NF is in 2NF; and
any relation in 2NF is in 1NF.
4. Normalization
May 2005 91.2914 4
We consider a relation in BCNF to be fully normalized.
The benefit of higher normal forms is that update semantics for
the affected data are simplified.
This means that applications required to maintain the database
are simpler.
A design that has a lower normal form than another design has
more redundancy. Uncontrolled redundancy can lead to data
integrity problems.
First we introduce the concept of functional dependency
5. Functional Dependencies
91.2914 5
Functional Dependencies
We say an attribute, B, has a functional dependency on
another attribute, A, if for any two records, which have
the same value for A, then the values for B in these two
records must be the same. We illustrate this as:
A B
Example: Suppose we keep track of employee email
addresses, and we only track one email address for each
employee. Suppose each employee is identified by their
unique employee number. We say there is a functional
dependency of email address on employee number:
employee number email address
6. Functional Dependencies
91.2914 6
EmpNum EmpEmail EmpFname EmpLname
123 jdoe@abc.com John Doe
456 psmith@abc.com Peter Smith
555 alee1@abc.com Alan Lee
633 pdoe@abc.com Peter Doe
787 alee2@abc.com Alan Lee
If EmpNum is the PK then the FDs:
EmpNum EmpEmail
EmpNum EmpFname
EmpNum EmpLname
must exist.
7. Functional Dependencies
91.2914 7
EmpNum EmpEmail
EmpNum EmpFname
EmpNum EmpLname
EmpNum
EmpEmail
EmpFname
EmpLname
EmpNum EmpEmail EmpFname EmpLname
3 different ways
you might see FDs
depicted
9. Transitive dependency
91.2914 9
Transitive dependency
Consider attributes A, B, and C, and where
A B and B C.
Functional dependencies are transitive, which
means that we also have the functional dependency
A C
We say that C is transitively dependent on A
through B.
10. Transitive dependency
91.2914 10
EmpNum EmpEmail DeptNum DeptNname
EmpNum EmpEmail DeptNum DeptNname
DeptName is transitively dependent on EmpNum via DeptNum
EmpNum DeptName
EmpNum DeptNum
DeptNum DeptName
11. Partial dependency
91.2914 11
A partial dependency exists when an attribute B is
functionally dependent on an attribute A, and A is a
component of a multipart candidate key.
InvNum LineNum Qty InvDate
Candidate keys: {InvNum, LineNum} InvDate is
partially dependent on {InvNum, LineNum} as
InvNum is a determinant of InvDate and InvNum is
part of a candidate key
12. First Normal Form
91.2914 12
First Normal Form
We say a relation is in 1NF if all values stored in the
relation are single-valued and atomic.
1NF places restrictions on the structure of relations.
Values must be simple.
13. First Normal Form
91.2914 13
The following in not in 1NF
EmpNum EmpPhone EmpDegrees
123 233-9876
333 233-1231 BA, BSc, PhD
679 233-1231 BSc, MSc
EmpDegrees is a multi-valued field:
employee 679 has two degrees: BSc and MSc
employee 333 has three degrees: BA, BSc, PhD
14. First Normal Form
91.2914 14
To obtain 1NF relations we must, without loss of
information, replace the above with two relations -
see next slide
EmpNum EmpPhone EmpDegrees
123 233-9876
333 233-1231 BA, BSc, PhD
679 233-1231 BSc, MSc
15. First Normal Form
91.2914 15
EmpNum EmpDegree
333 BA
333 BSc
333 PhD
679 BSc
MSc679
EmpNum EmpPhone
123 233-9876
333 233-1231
679 233-1231
An outer join between Employee and EmployeeDegree will
produce the information we saw before
Employee
EmployeeDegree
16. Boyce-Codd Normal Form
91.2914 16
Boyce-Codd Normal Form
BCNF is defined very simply:
a relation is in BCNF if it is in 1NF and if every
determinant is a candidate key.
If our database will be used for OLTP (on line transaction
processing), then BCNF is our target. Usually, we meet this
objective. However, we might denormalize (3NF, 2NF, or
1NF) for performance reasons.
17. Second Normal Form
91.2914 17
Second Normal Form
A relation is in 2NF if it is in 1NF, and every non-key attribute
is fully dependent on each candidate key. (That is, we don’t
have any partial functional dependency.)
• 2NF (and 3NF) both involve the concepts of key and
non-key attributes.
• A key attribute is any attribute that is part of a key;
any attribute that is not a key attribute, is a non-key
attribute.
• Relations that are not in BCNF have data redundancies
• A relation in 2NF will not have any partial dependencies
18. Second Normal Form
91.2914 18
LineNum ProdNum QtyInvNum
InvNum, LineNum ProdNum, Qty
Since there is a determinant that is not a
candidate key, InvLine is not BCNF
InvLine is not 2NF since there is a partial
dependency of InvDate on InvNum
InvDate
InvDateInvNum
There are two
candidate keys.
Qty is the only non-
key attribute, and it is
dependent on InvNum
InvLine is
only in 1NF
Consider this InvLine table (in 1NF):
19. Second Normal Form
91.2914 19
LineNum ProdNum QtyInvNum InvDate
InvLine
The above relation has redundancies: the invoice date is
repeated on each invoice line.
We can improve the database by decomposing the relation
into two relations:
LineNum ProdNum QtyInvNum
InvDateInvNum
Question: What is the highest normal form for these
relations? 2NF? 3NF? BCNF?
20. 91.2914 20
Is the following relation in 2NF?
inv_no line_no prod_no prod_desc qty
21. 91.2914 21
2NF, but not in 3NF, nor in BCNF:
since dnumber is not a candidate key and we have:
dnumber dname.
EmployeeDept
ename ssn bdate address dnumber dname
22. Third Normal Form
91.2914 22
Third Normal Form
• A relation is in 3NF if the relation is in 1NF and all
determinants of non-key attributes are candidate keys
That is, for any functional dependency: X Y, where Y is
a non-key attribute (or a set of non-key attributes), X is a
candidate key.
• This definition of 3NF differs from BCNF only in the
specification of non-key attributes - 3NF is weaker than
BCNF. (BCNF requires all determinants to be candidate
keys.)
• A relation in 3NF will not have any transitive dependencies
of non-key attribute on a candidate key through another
non-key attribute.
23. Third Normal Form
91.2914 23
EmpNum EmpName DeptNum DeptName
EmpName, DeptNum, and DeptName are non-key attributes.
DeptNum determines DeptName, a non-key attribute, and
DeptNum is not a candidate key.
Consider this Employee relation
Is the relation in 3NF? … no
Is the relation in 2NF? … yes
Is the relation in BCNF? … no
Candidate keys
are? …
24. Third Normal Form
91.2914 24
EmpNum EmpName DeptNum DeptName
We correct the situation by decomposing the original relation
into two 3NF relations. Note the decomposition is lossless.
EmpNum EmpName DeptNum DeptNameDeptNum
Verify these two relations are in 3NF.
25. 91.2914 25
student_no course_no instr_no
Instructor teaches one
course only.
Student takes a course
and has one instructor.
In 3NF, but not in BCNF:
{student_no, course_no} instr_no
instr_no course_no
since we have instr_no course-no, but instr_no is not a
Candidate key.