 |
|
www.thirdwave-websites.com/ci310 |
CI-310 : October 4, 2000
- Return Quiz One-Two
- Return Assignment Three
- Distribute Quiz Three
- Collect Personal Project Definitions
- Distribute Group Project Possibilities
|
|
|
|
warnings
|
Some Web Tricks (see handout)
- Sounds
- Rollovers
- Resume
- Colors
Chapter 6: Managing Data Resources
DBMS: data base management system
Terms:
- field
- record
- file
- database
- entity
- attribute
- key field
Accessing Records from computer files
- Sequential File Organization
- Direct (or Random) File Organization
- ISAM: Indexed Sequential Access Method (benefit: scalability)
- Direct File Access Method: transform algorithms find the record
Existing Problems with the Traditional File Environment
- Isolated Silos develop in isolation
- data redundancy
- program-data dependence
- lack of flexibility
- poor security
- lack of data-sharing and availability
Solution? The Database!
A collection of data organized to serve many applications efficiently by centralizing the data and minimizing redundant data.
- Data Definition Language
- Data Manipulation Language (SQL)
- Data Dictionary
- Logical and Physical Views of Data (pg. 186)
Types of Databases
- Relational Data Model.
- Relates data stored in one table to data in another table as long as the two tables share a common data element.
- Rows=records=tuples
- Main Commands: select, project, join.
Select creates a subset of rows
Project creates a subset of columns
Join combines tables to form a new view
- Hierarchical Data Model (one-to-many)
- Network Data Models (many-to-many)
- Term: legacy system
- Object-Oriented Databases: not only numbers and text but also video, sound, etc.
- Object-Relational Hybrids.
Designing Databases
Two steps: conceptual design and physical design.
Entity-Relationship Diagram (see figure 6-13)
Streamlining: normalization. 1NF, 2NF, 3NF, 4NF.
Centralized vs. Distributed Databases.
Database Trends
Multidimensional Data Analysis (aka OLAP- online analytical processing) (figure 6-17)
Data Warehousing and Data Marts
A data warehouse is a database that integrates current and historical data throughout the company, from different systems and sources. It permits compilation of a big-view without interfering with existing, disparate legacy operational systems.
A data mart is a subset of a data warehouse in which some of the company's data is placed into a new database for a small, specific group of users.
Hypermedia Databases fields consisting of linked multi-media
Web-Linked Databases.
Management Requirements for DB Systems
Database is a way of life; it is more of an organizational (political and $$$ ) issue rather than a choice between Access and Oracle.
- Data Administration. CIO. Info Policy.
- Data Planning and Modeling Methodology. enterprise analysis
- DB Technology and Management
- Users
Summary, p. 203- 204.
To Do For Next Class, 10/11/00
- Read Chapter 7, skim first half of Chapter 8.
- Complete Quiz Three(5%).
- Begin Working on your Personal Project (webpage).
- Draw a chart of the basic structure.
- Build skeletons of your pages.
- Workshop next week.