PPT - Structuring Database for Accounting Commerce Notes | EduRev

 Page 1


Chapter 1
Page 2


Chapter 1
Learning Objective
? Define Database Management System (DBMS) and 
database
? Describe the advantages and disadvantages of DBMS 
to file based system.
? Analyses structure models in Database
Page 3


Chapter 1
Learning Objective
? Define Database Management System (DBMS) and 
database
? Describe the advantages and disadvantages of DBMS 
to file based system.
? Analyses structure models in Database
Definitions
Database:
? A very large, integrated collection of data.
? Models real-world enterprise.
? Entities (e.g., students, courses)
? Relationships (e.g., Madonna is taking CS564)
Database Management System (DBMS)
? a software package designed to store and manage databases.
? Examples of Database Applications:
• Banking: all transactions
• Airlines: reservations, schedules
• Universities:  registration, grades
Page 4


Chapter 1
Learning Objective
? Define Database Management System (DBMS) and 
database
? Describe the advantages and disadvantages of DBMS 
to file based system.
? Analyses structure models in Database
Definitions
Database:
? A very large, integrated collection of data.
? Models real-world enterprise.
? Entities (e.g., students, courses)
? Relationships (e.g., Madonna is taking CS564)
Database Management System (DBMS)
? a software package designed to store and manage databases.
? Examples of Database Applications:
• Banking: all transactions
• Airlines: reservations, schedules
• Universities:  registration, grades
Purpose of Database Systems
? In the early days, database applications were built directly on top of 
file systems
? Drawbacks of using file systems to store data:
? Data redundancy and inconsistency
? Multiple file formats, duplication of information in different files
? Difficulty in accessing data 
? Need to write a new program to carry out each new task
? Data isolation — multiple files and formats
Page 5


Chapter 1
Learning Objective
? Define Database Management System (DBMS) and 
database
? Describe the advantages and disadvantages of DBMS 
to file based system.
? Analyses structure models in Database
Definitions
Database:
? A very large, integrated collection of data.
? Models real-world enterprise.
? Entities (e.g., students, courses)
? Relationships (e.g., Madonna is taking CS564)
Database Management System (DBMS)
? a software package designed to store and manage databases.
? Examples of Database Applications:
• Banking: all transactions
• Airlines: reservations, schedules
• Universities:  registration, grades
Purpose of Database Systems
? In the early days, database applications were built directly on top of 
file systems
? Drawbacks of using file systems to store data:
? Data redundancy and inconsistency
? Multiple file formats, duplication of information in different files
? Difficulty in accessing data 
? Need to write a new program to carry out each new task
? Data isolation — multiple files and formats
? Drawbacks of using file systems (cont.) 
? Integrity problems
? Integrity constraints  (e.g. account balance > 0) become 
“buried” in program code rather than being stated explicitly
? Hard to add new constraints or change existing ones
? Atomicity of updates
? Failures may leave database in an inconsistent state with 
partial updates carried out
? E.g. transfer of funds from one account to another should either 
complete or not happen at all