Technology Guide 3

Data & Database

Agenda

• Definition

• File processing problems

• Database

• Selection criteria

Definition

• Element– Bit, byte, field, record, file, database– Entity, attribute, key field

• Organization & access method– Sequential file– Indexed sequential file– Direct or random file

Agenda

• Definition

• File processing problems

• Database

• Selection criteria

File Processing Problems

• Redundancy

• Inconsistency

• Isolation

• Security

• Integrity

• Data/program independence

Agenda

• Definition

• File processing problems

• Database

• Selection criteria

Database

• Types

• Structure

• Models

• Creation

• Topology

Database Types

• Business database• Geographical information database• Knowledge database / deductive database• Multimedia database• Data warehouse• Data marts• Multimedia and hypermedia database• Object-oriented database

Database Structure

• Data definition language– Schema & subschema

• Data Manipulation language– Structured Query Language (SQL)– Query By Example (QBE)

• Data dictionary

Database Models• Hierarchical

– One to many– Usage

• Network– Many to many– Usage

• Relational– Normalization– Usage

• Object-oriented– Usage

Database Creation

• Conceptual design– Logical view– Entity-relationship (ER) diagram

• Entity, entity classes, instance, attributes, identifier

• Relationships, binary relationships

– Normalization

Database Creation

• Physical design– Physical view– Data topology (organization)

• Centralized• Distributed database

– Replicated database– Partitioned

– Access method– Security

Agenda

• Definition

• File processing problems

• Database

• Selection criteria

Selection Criteria

• User’ needs (type of application)• Compatibility• Portability• Reliability• Cost• Feature• Performance• Vendor’s support• Others?

Points to Remember

• Definition

• File processing problems

• Database

• Selection criteria

Discussion Question

• How can a database help an organization?

• Why normalization is very important for building a database?

• What kind of database model(s) is most suitable for E-bay?

• Do you see any problem(s) of the database in your organization?

Assignment

• Review technology guides 1-3

• Read technology guide 4, chapter 1

• Group Assignment

• Research paper