4300 Chapter 1

what do good decisions require?

good information

what is good information derived frm

data (raw facts)

where is data stored

in databases

where did databases evolve from

computer file systems

what types of data are stored

• end user data

• metadata

desktop database

single user database on a personal computer

workgroup database

Multiuser database that supports a small number of users or a specific department

enterprise database

Multiuser database: supports many users across multiple departments

Evolution of Data Processing: 1st Manual file systems

accomplished through a system of file folders and filing cabinets

Evolution of Data Processing: 2nd computerized file systems

data processing (DP) specialist created a computer based system that would track data and produce required reports

Evolution of Data Processing: 3rd File System Redux: Modern End-User Productivity Tools

Includes spreadsheet programs such as Microsoft Excel

islands of information

scarttered data locations

what do islands of information increase the probability of

having different versions of the same data

data dictionary

stores definitions of data elements and their relationships

data storage management

performance tuning ensures efficient performance

data transformation and presentation

data is formatted to conform logical expectations

security management

enforces user security and data privacy

multiuser asccess control

sophisticated algorithms ensure that multiple users can access the database concurrently without compromising its integrity

back up and recover management

enables recover of the database after a failure

data integrity management

minimizes redundancy and max consistency

querly language

lets the user specify what must be done without having to specify how

structured QL

de facto query language and data access standard supported by the majority of DBMS vendors

what defines the database structure

database design

why were DBMS created?

to address the file systems inherent weaknesses

how can databases be defined

according to the number of users locations as well as data usage and structure

database systems provide?

structural independence

database systems support?

data independence

database systems reduce?

data redundancy resulting in fewer anomalies