The document discusses key concepts in database design including fields, records, database management systems (DBMS), normalization, and the roles of a database administrator. It explains that a field is the smallest unit of data, a record contains related fields, and a DBMS provides an interface between data files and programs. The document also covers database normalization forms, logical and physical views of data, and functions of a DBMS like ensuring data integrity and security.

1. DATABASE DESIGN
SUBMITTED BY :
SURBHI JAGGI
NEELESH VAISH

2. Fields
A field is the physical implementation of a data
attribute. They are the smallest unit of meaningful
data.
A primary key is a field
A descriptive field is any
whose values identify one
other (nonkey) field that
and only one record in a file.
stores business data.
A secondary key is an
alternate identifier for a
record.
A foreign key is a pointer to
a record in a different file.

3. Records
A record is a collection of fields arranged in a
predefined format.
 Fixed-length record structures
 Variable-length record structures
A blocking factor is the number of logical
records included in a single read or write
operation (from the computer’s perspective).
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4. DBMS Environment
Skills
Inventory
Profit
Sharing DBMS • Skills Data
Inventory •Profit Sharing Data
•Benefits Data
Employee
Benefits
Application

5. Objectives Of
Database
 Controlled Redundancy
 Ease of learning and use
 Data Independence
 More Information at Low Cost
 Accuracy and Integrity
 Recovery From Failure
 Privacy and security
 Performance
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6. Key Terms
 Users View
 Processing
 Data Model
 Data File
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7. What is DBMS?
“ In a Database Environment, a DBMS is the
software that provides the interface between
the data file on disk and the program that
requests processing. ”
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8. Some Important Terms
 DML – or ‘Data Manipulation Language’
DML manipulates data, i.e. it specifies what is required
 DDL – or ‘Data Definition Language’
DDL describes how the data is structured
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9. Functions of a DBMS
 Storing, Retrieving and Updating data
 Creating program and data independence
 Enforcing Procedures for data integrity
 Reducing data redundancy
 Providing security facilities for defining users and
enforcing authorizations
 Reducing Physical storage requirements by
separating the logical and physical aspects of the
database.
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10. LOGICAL AND
PHYSICAL
VIEWS OF DATA

11. PHYSICAL VIEW OF DATA
 It is the way data exist in physical storage.
 It deals with how data stored, accessed, or
related to other data in storage.
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12. LOGICAL VIEW OF DATA
 what the data look like, regardless of how
they are stored.
 The logical views are the user’s view, the
programmer’s view, and the overall logical
view, called a schema.
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13. SCHEMAS
 It is the view that helps the DBMS (database
management system) decide what data in
storage it should act upon as requested by the
application program.
 Example: Is the arrival and departure display at
an airport.
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16. SUBSCHEMAS
 It is the programmer’s (pilot’s) view.
 Many subschemas can be derived from one
schema.
 Example: just as different pilots visualize
different views of landing approach, although
all (it is hoped) arrive at the sheduled time
indicated on the CRT screen display (schema).
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18. What is an ENTITY ??
AN ENTITY IS A THING OR OBJECT OF
IMPORTANCE ABOUT WHICH DATA MUST BE
CAPTURED. ALL THINGS AREN'T
ENTITIES—ONLY THOSE ABOUT WHICH
INFORMATION SHOULD BE CAPTURED. AN
ENTITY IS SOMETHING THAT EXISTS
INDEPENDENTLY .

21. Cardinality

22. DATABASE NORMALIZATION
 Database normalization is a design technique by
which relational database systems are structured in
such a way as to make them less vulnerable to certain
types of logical inconsistencies and anomalies.
 Tables can be normalized to varying degrees:
relational database theory defines "normal forms" of
successively higher degrees of stringency.
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23. Data Normalization
An logical entity (or physical table) is in first normal
form if there are no attributes (fields) that can have
more than one value for a single instance (record).
An logical entity (or physical table) is in second normal
form if it is already in first normal form and if the values
of all nonprimary key attributes are dependent on the
full primary key.
An logical entity (or physical table) is in third normal
form if it is already in second normal form and if the
values of all nonprimary key attributes are not
dependent on other nonprimary key attributes .
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24. First Normal Form
 The criteria for first normal form :
 A table must be guaranteed not to have
duplicate records.
 There must not be any repeating groups, ie,
no attributes which occur a different number
of times on different records.
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25. R NO. NAME DOB SUBJECT GRADE
1 ABC 2 MARCH,1989 OS A
BS A+
CONA B+
2 DEF 25 DECEMBER,92 BS A
ENGLISH A
R NO. NAME DOB SUBJECT GRADE
1 ABC 2 MARCH,1989 OS A
1 ABC 2 MARCH,1989 BS A+
1 ABC 2 MARCH,1989 CONA B+
2 DEF 25 DECEMBER,92 BS A
2 DEF 25 DECEMBER,92 ENGLISH A

26. Second Normal Form
 Criteria for second normal form :
 The table must be in 1NF
 None of the non-prime attributes of the
table are functionally dependant on a part of
a candidate key.
 None of a 1NF’s candidate keys are
composite.
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27. R NO. NAME DOB
1 ABC 2 MARCH,1989
2 DEF 25 DECEMBER,92
R NO. SUBJECT GRADE
1 OS A
1 BS A+
1 CONA B+
2 BS A
2 ENGLISH A

28. Third Normal Form
 Criteria for third normal form:
 Table must be in 2NF.
 There are no non-trivial functional
dependencies between two non prime
attributes.
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29. SSN PNUMBER HOURS ENAME PNAME PLOCATION
SSN PNUMBER HOURS SSN ENAME
PNUMBER PNAME PLOCATION

30. Roles of Database
Administrator
Managing data activities
Managing database structure
Managing DBMS
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