1. Data & Databases Basic Data Fundamentals

2. Data vs Information zData: facts Computer systems store data. zInformation: facts organized for a specific application Information is the output of a computer system

3. Data zAtomic Data Data in units that cannot be subdivided yFirst Name, Price, etc. zBinary Large Objects (BLOB) Images and figures yPictures, Cartoons zObjects Data and associated processes ySpreadsheet tables, graphics components

4. Atomic Data Most current systems store atomic data. Atomic data is typically made up of characters (letters and numbers) stored in coded groups of 8 bits called bytes. ASCII American Standard Code for Information Interchange EBCDIC Extended Binary Coded Decimal Interchange Code

5. Byte **************** Parity Bit 7 Data Bits 2 7 = 128 distinct characters

6. Atomic Data Because atomic variables are made up of a relatively small number of codes, computers can interpret and manipulate them

7. Binary Large Objects These are typically bit mapped pictures or images (such as FAXs) that are stored. Parts of these pictures have meaning (unlike atomic data). Digital pictures, video clips, stored images and signatures are BLOBs. PIXEL blobs are usually stored as pixel codes that represent a point on a video screen

8. Bit Maps 1028 High Resolution 1028 x 640 = 657,920 pixels Black & White = 1 bit per pixel 256 tone Color = 8 bits per pixel 640

9. Image Processing Images cannot be processed easily (other than displayed and scaled) by normal technology and usually require attached atomic indexes. Text images can be con- verted although the software is not fully reliable.

10. Objects Objects combine data and the processes that manipulate it. An example of an object is a spreadsheet table imported with the manipulation rules. zEncapsulation zFormal Interface for Messages zInheritance

11. Object Processing Object databases are new technologies with immature design methodologies. They promise extensive code reuse and easy system development if the tech- nology proves itself.

12. Data, Metadata and Business Rules Metadata is data about data, the structure descriptions of the stored files. Metadata includes location, format, field name, data description, etc. Business rules include editing and processing rules as well as automatic procedures that must be processed for accurate data.

13. Data Access Technology zFlat File structures. Data in one location; metadata and business rules in programs zDatabase Management Systems Data and metadata together; business rules in programs zObject Oriented systems Data, metadata and business rules together

14. Database Approach Program 1 Program 2 Program 3 Metadata Data Program 1 Program 2 Program 3 Meta- Data FILE SYSTEM DATABASE

15. Distribution Strategies for Databases Centralized Data and Processing: Dumb terminal with "screen scraping". Intelligent Terminal: Data and processing centralized; data preparation and display on remote devices. Distributed Logic: Data storage distributed; processed at the optimal location. A version of parallel processing. Client Server: Data (usually departmental) maintained on a server. Subsetting occurs on the server, processing on client machines. Distributed Database: Data distributed among different locations; processing access data wherever it is located. Data may be replicated or partitioned.

16. Central Data with Dumb Terminals Data

17. Simple Client/Server

18. Multi-Tier Client/Server Application Business Rules Data

19. Distributed Processing

20. Data Trends zCentralized and Client/Server systems zMulti Layered architectures zObjects and encapsulation zData driven organizations zData warehousing

21. DATA