Lec_1_database_vs_file_system_basic_concept

Lecture 1 from database system fromthomas connolly and carolyn begg

1. Lecture 1
Database System (INFT-4006)

2. Course Overview
•Introduction to data, database, data models
•File organization and Transaction Processing
•Concurrency Control
•Backup and Recovery
•Query processing and optimization
•Database Programming (with SQL)
•Integrity and Security
•Database Administration
•Physical Database design and Tuning
•Distributed Database
•Emerging Research trends in Database Systems (NoSQL, GraphQL, Blockchain)

3. Course overview
•4 assignments (2 assignments before Midterm exam, 2
assignments after Midterm exam)
•4 Quizzes
•Database Project Presentation
•Viva Voce activity

4. Reference Books
•Database Systems: A Practical Approach to Design,
Implementation and Management, 6ᵗʰ Edition by Thomas
Connolly and Carolyn Begg (AKA C&B)
•Database Systems: The Complete Book, 2ⁿᵈ Edition by
Hector-Gracia Molina, Jeffery D. Ullman, Jennifer Widom
•Database System Concepts, 6ᵗʰ Edition by Avi Silberschatz,
Henry F. Korth and S. Sundarshan
•Database Management Systems, 3ʳᵈ Edition by Raghu
Ramakrishnan, Johannes Gehrke

5. Outlines
•Database System
•File-Based Systems
•Limitations of File-Based Systems

6. Data, Data,
Data……

7. What is Data?
Data is a
collection of raw
facts and figures
It is collected
from different
sources
It is collected for
different
purposes

8. •Data is precious corporate resource
•It provides correct information for making proper and
timely decisions
•It provides operational activities of an organization
•It is not possible to make good decision if data is not
available in desired format

9. Metadata
Thedescriptionofdata(dataaboutdata)is
called“Metadata”or“Systemcatalog”or“Data
dictionary”

10. File
Afileisacollectionofrecords,which
contains logically related data

11. Fields

12. A collection of application
programs that perform services for
the end-users, such as the
production of reports. Each
program defines and manages it
owndata
File-Based
Approach

13. •Data is divided into separate files, each file
containing specific information
•Files have specific format and structure
based on application program being used e.
g. text, images, documents etc.
•Files are organized into directories (or
folders) to create a hierarchical structure
•Application program directly access and
manipulate these files
How it
works

14. Limitation of File-based System
•Separation and Isolation of Data
•Duplication of Data
•Data dependance
•Incompatible File formats
•Fixed Queries

15. Separation and
Isolation of Data
•Data is stored in separate files,
often with no inherent
relationships between them
•Retrieving information that spans
multiple files can be complex and
time-consuming
•Sharing data between different
applications or departments is
challenging due to data isolation

16. Duplication of
Data
(Redundancy)
•The same data can exist in
multiple files, leading to
inconsistencies if updates are not
synchronized
•Duplicate data consumes
unnecessary storage resources
•Keeping multiple copies of data
tdt i dditil

17. Data
Dependency
•Data items often depend on
other data items, creating
complex relationships
•Modifying one piece of data
may require changes in
multiple files, leading to errors
•Applications must handle
complex data dependencies,
making development more

18. Incompatible File
Formats
•Different applications may use
different file formats, hindering
data sharing and integration
•Converting data from one format
to another can be time-consuming
and error-prone
•Systems using different file
formats may have difficulty
exchanging data

19. Fixed Queries
Complex
queries can be
slow and
inefficient to
execute
Users are
restricted to
predefined data
access patterns
File-based
systems
typically
support
predefined
queries,
limiting ad-hoc
li

20. Database
“Asharedcollectionof
logicallyrelateddata
anditsdescription,
designedtomeetthe
informationneedsofan
organization”

21. Database
•Database is collection of information
managed by Database management
system
•It is a single large collection (repository)
of data shared among users
•All data items are integrated with
minimum duplication
•Database is shared corporate resource
•Database not only contains operational
databutalsodescriptionofdata

22. Database
•The self describing nature of database
provides “program-data independence”
•The definition of data is separated from the
application program
•The structure of data is not affected by the
program and vice versa
•If new data structures are added or existing
data structures are modified, they do not
affect the application program (if program
does not directly depend on what has been
modified)
•Forexampleifweremoveafieldthatis

23. Branch Staff
PropertyForRent Client
LeasePrivateOwner
Ha
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Oversees
ViewsOffers
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s
Leased
By
Hold
s

24. What is meant by
logically related?

25. ANY QUESTIONS?