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1. Database Assignment
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2. Type of Data to Store
 Type of Data
◦ Raw data
◦ Pre-processed
◦ Compressed
 Frequency of Data Storage for Sensor Data
◦ Tradeoff between precision and quantity

3. Database Types / Data Models
 Relational
 OO
 Hybrid (Object-Relational)
 Temporal
 Deductive
 Others
◦ Spatial, …

4. Data Representations
 Relational
◦ We all know…flat tables of atomic attributes
with foreign key relationships
 OO
◦ Complex data reps
 multivalued, composite
 Temporal
◦ Relational model: add valid start, end dates to
each table (versions of info and when valid)
◦ Includes time, events, durations…

5. Operations
 DDL/DML (data def/manip languages)
◦ SQL
◦ OQL
 Update operations
◦ Built-in insert, delete, update
◦ Stored procedures for triggers, active (ECA)
rules

6. Example Operations for Temporal
Databases
 INCLUDES
◦ Rows valid in a certain time period
 BEFORE/AFTER a time condition
 Set operations
◦ Union, intersection of 2 time periods

7. Distributed vs. Centralized
 Centralized database can produce a
bottleneck
◦ Large volume of data input
◦ Large database
◦ Large volume of queries
 In distributed databases, data
consistency, replication, and retrieval can
be more problematic
◦ Consistency of schemas
◦ Retrieval in case the data location is not known
◦ Communication overhead to ensure database
consistency

8. Types of Database Systems
 Commercial
◦ DB2
◦ Empress
◦ Informix
◦ Oracle
◦ MS Access
◦ MS SQL
◦ Sybase
 Free
◦ Berkeley DB
◦ PostgreSQL
◦ MySQL

9. Database System
 Database:
A collection of related data.
 Data:
Known facts that can be recorded and have an
implicit meaning.
 Database Management System
(DBMS):
A software package/system to facilitate the
Define, Construct, Manipulate and Share
functions of a computerized database.

10. Typical DBMS Functionality
 Define a particular database in terms of its data types,
structures, and constraints
 Construct or Load the initial database contents on a
secondary storage medium
 Manipulate the database:
◦ Retrieval: Querying, generating reports
◦ Modification: Insertions, deletions and updates to its content
◦ Accessing the database through Web applications
 Share a database allows multiple users and programs to
access the database simultaneously

11. Database system environment

12. Example
 A UNIVERSITY database for maintaining information
concerning students, courses, and grades in a
university environment
 We have:
STUDENT file stores data on each student
COURSE file stores data on each course
SECTION file stores data on each section of each
course
GRADE_REPORT file stores the grades that students
receive
PREREQUISITE file stores the prerequisites

13. Example of a simple database

14. Database manipulation
 Database manipulation involves querying
and updating
 Examples of querying are:
Retrieve a transcript
List the prerequisites of the “Database”
course
 Examples of updating are:
Enter a grade of “A” for “Smith” in
“Database” course

15. Advantages of using the DBMS
approach
 Restricting unauthorized access to data
 Providing Storage Structures (e.g.
indexes) for efficient Query Processing
 Providing backup and recovery services
 Providing multiple interfaces to different
classes of users
 Representing complex relationships
among data