Intro to Database Week 1 (midterm)

Data

Known facts that can be recorded

Database

Collection of related data in DBMS

Database Management System (DBMS)

A (computer system/general purpose software) that eases creation, usage, and maintenance of databases

Database System

Database + DBMS

Meta-data

Data types, structures, and rules of data in the database (data about the data in the dictionary)

Query

Retrieval of data from database

Transaction

Process of reading/writing from/to database (smallest unit in DBMS)

What’s the most important DBMS Functionalities

1. Define Database

2. Load database

3. Manipulate (Retrieve, Modify, Access)

4. Sharing

5. Security

6. Presentation of Data

What are the main CHARACTERISTICS of database approach

1. Self-describing: DBMS catalog stores all description of database

2. Program-data independence

3. Support multiple views of data: choose what to see from data

4. Sharing data & multi-user transaction

Program-data Independence

changing data structure/types without having to change programs that use the DBMS

Data Abstraction

Hide storage details and present users with conceptual view only

DBMS Concurrency

many users can do transactions at the same time

Online transaction processing (OLTP)

major part of database applications that allow hundreds of concurrent transactions

What are the 3 types of DB users (Actors)

1. Database Administrator

2. Database Designer

3. End-users

What is the database administrator responsible for

1. Manage database

2. Manage access of database & security

3. Manage H/W and S/W related to DB

4. Monitor efficiency & response time

What is the database designer responsible for

1. Defining database structure & rules

2. Communicate with users to understand their needs

What are the 4 types of end-users and their responsibilities

1. Casual: use DB when needed

2. Naïve (Parametric): use previously made programs to use database ex: largest user amount, bank tellers

3. Stand-alone: use ready-to-use packaged applications

4. Sophisticated: Use tools to work with DB. ex: Analysts, engineers

What are the ADVANTAGES of using database approach

1. Control redundancy

2. Maintain integrity

3. Access control

4. Backup

5. Many views of same data

6. Complex relationship

7. Efficient queries using storage structures

8. Persistent storag

What are the implications of using database approach

1. Enforce standards

2. Reduced development time

3. Flexibility in modifying the DB

4. Up-to-date data in DB

5. Economies of scale (avoid waste of resources)

What is the History of DB technology

1. Hierarchal Systems: basic network and inverted file system

2. Relational model: most famous, modern database system

3. Object Oriented: OOP language, more features than rational

4. Data on web: Mostly using XML

5. Object-Relational: Relational + OOP

When should you NOT use DBMS

1. High initial cost & time for Development

2. Simple applications

3. No need for real-time usage

4. No need for concurrency