1. CPSC-608 Database Systems
Fall 2018
Instructor: Jianer Chen
Office: HRBB 315C
Phone:
Notes 2

2. Undergraduate Database
A Quick Review on
Undergraduate Database

3. Database is just another model of information processing
(in disks)
Then why study DB?
Much more data, regular data techs would be very inefficient: How should data be stored?
Operations are simpler & more specific: How do we take advantage of it?
New programming languages for the above.
(ACID) Reliability, security, consistency, currency
π, σ, ρ,
∩, ⋃, \,
╳, ⋈, ⋈C
SQL

4. Database is just another model of information processing
(in disks)
Then why study DB?
Much more data, regular data techs would be very inefficient: How should data be stored?
Operations are simpler & more specific: How do we take advantage of it?
New programming languages for the above.
(ACID) Reliability, security, consistency, currency
π, σ, ρ,
∩, ⋃, \,
╳, ⋈, ⋈C
SQL

5. How Should Data be Stored?
Large volume: cannot fit in memory, thus in general stored in disks;

6. How Should Data be Stored?
Large volume: cannot fit in memory, thus in general stored in disks;
Regular files are not organized enough;

7. How Should Data be Stored?
Large volume: cannot fit in memory, thus in general stored in disks;
Regular files are not organized enough;
Hierarchical structure and network structure were considered, but became less popular;

8. How Should Data be Stored?
Large volume: cannot fit in memory, thus in general stored in disks;
Regular files are not organized enough;
Hierarchical structure and network structure were considered, but became less popular;
Table structures (2-dimensional arrays) are currently the most popular model (relational model);

9. How is Information Represented?
How can everything be given by tables?

10. How is Information Represented?
How can everything be given by tables?
Well, information consists of objects/items and relationships among items;

11. How is Information Represented?
How can everything be given by tables?
Well, information consists of objects/items and relationships among items;
An item has certain properties, which can be listed in a row. Thus, a collection of similar items can be given as a table, one row for an item;

12. How is Information Represented?
How can everything be given by tables?
Well, information consists of objects/items and relationships among items;
An item has certain properties, which can be listed in a row. Thus, a collection of similar items can be given as a table, one row for an item;
A relationship can be given by listing each item group that satisfies the relationship;

13. How is Information Represented?
How can everything be given by tables?
Well, information consists of objects/items and relationships among items;
An item has certain properties, which can be listed in a row. Thus, a collection of similar items can be given as a table, one row for an item;
A relationship can be given by listing each item group that satisfies the relationship;
High-level representation of information (E-R Diagram: read Chapter 4)

14. Table structures (terminologies)
Information is stored in tables (≡ relations);
Each column of a table is an attribute, with an attribute name;

15. Table structures (terminologies)
Information is stored in tables (≡ relations);
Each column of a table is an attribute, with an attribute name;
A database is a collection of relations;

16. Table structures (terminologies)
Information is stored in tables (≡ relations);
Each column of a table is an attribute, with an attribute name;
A database is a collection of relations;
An example table (Account):
Account No.
Balance
Type
12345
20,520
checking
23456
1,000,000 CD
34567 26
savings
45678
7,023

17. Table structures (terminologies)
A relation schema gives the name of the relation and its attributes;

18. Table structures (terminologies)
A relation schema gives the name of the relation and its attributes;
A database schema gives the schemas for all relations in the database;

19. Table structures (terminologies)
A relation schema gives the name of the relation and its attributes;
A database schema gives the schemas for all relations in the database;
Schemas affects how the data is stored;

20. Table structures (terminologies)
A relation schema gives the name of the relation and its attributes;
A database schema gives the schemas for all relations in the database;
Schemas affects how the data is stored;
Database schemas are given and altered using data definition language (DDL);

21. Table structures (terminologies)
A relation schema gives the name of the relation and its attributes;
A database schema gives the schemas for all relations in the database;
Schemas affects how the data is stored;
Database schemas are given and altered using data definition language (DDL);
Only database administrator can use DDL.

22. What is a good DB schema?

23. What is a good DB schema?
What is a good table structure? Fat or thin?

24. What is a good DB schema? What is a good table structure? Fat or thin?
More important: how can tables guarantee information consistency?

25. What is a good DB schema? What is a good table structure? Fat or thin?
More important: how can tables guarantee information consistency?
There is a beautiful theory (functional dependency) for constructing a good database schema;

26. What is a good DB schema? What is a good table structure? Fat or thin?
More important: how can tables guarantee information consistency?
There is a beautiful theory (functional dependency) for constructing a good database schema;
Read Chapter 3.

27. Database is just another model of information processing
(in disks)
Then why study DB?
Much more data, regular data techs would be very inefficient: How should data be stored?
Operations are simpler & more specific: How do we take advantage of it?
New programming languages for the above.
(ACID) Reliability, security, consistency, currency
π, σ, ρ,
∩, ⋃, \,
╳, ⋈, ⋈C
SQL