Introduction to Databases Chapter 1: Introducing Data and Data Management

Data Stream of raw, unorganized facts Single piece of data is single fact: – Refrigerator SSN manufactured 11/05/2006 Information: Data organized into form people can understand or use

Databases Ordered collections of related data elements Designed to meet organization’s information needs Designed to be shared by multiple users Help transform data into information – For example, used to transform store cash register transactions into sales reports

Example: Airline Ticketing & Reservations Company

Data Management Uses databases and database management software (DBMS) Allows organizations to: –Easily access data –Handle greater quantities of data –Share data –Reduce data redundancy (unwanted duplicate data)

Data Sources To understand what data is meaningful, examine company’s core business and processes Processes: Series of tasks that accomplish specific goal Primary processes help fulfill core business To carry out process, company needs resources and assets, such as: – Buildings and equipment – People – Money – Information from relevant data sources

Example: Car Rentals Core business – Rent cars Primary processes –Processes to manage fleet and service cars

Example: Car Rentals: Departmental Activities

Specific Data Sources Specific data important to company can be found in: – Current information held in business documents – Historic information – Human sources: Employees at different levels can provide different types of information about data

Human Data Sources

Data Flows Part of data collection process includes understanding how data flows through organization Data: Similar to water, flowing from source to destination However, unlike river, data may have many destinations, or data consumers

Data Concerns Data accuracy Data security Data organization Data access

Data Accuracy Involves ensuring accurate and correct data Inaccurate data: –Employee mistakes, shortcuts, and biases –Outdated –Poorly designed formulas or algorithms Maintaining data accuracy includes: –Verifying data sources –Managing data entry and manipulation

Data Security Processes and procedures implemented with goal of keeping data safe Basic data security categories include: –Access security –Physical security

Access Security Involves controlling user and application access to data, usually through one or more authentication methods To reduce data source’s vulnerability: –Reduce surface area (how exposed database is to access and manipulation by consumer audience ) As potential consumer audience increases, so do potential security concerns

Access Security

Physical Security Involves protecting data against physical corruption or loss Three basic tasks : –Protecting server Secure server in locked room with limited access –Ensuring storage media Use fault-tolerant disk system –Duplicating data Maintain duplicate of data on mirror image, or make data backups

Data Organization Forces structure on data Helps reduce amount of physical space data requires Helps minimize time required to locate and retrieve data Data standards: Help ensure that right amount of data is entered in same way for every data object

Data Access Data queries retrieve data, insert new data, or manipulate existing data Before database setup, determine: –Who needs access to data User roles or responsibilities –What level of access is needed Full or limited access –Type of access needed Directly or indirect through separate application

Summary Data are raw facts that organizations collect and transform into meaningful information Data and information are primary business resource Data management through databases help support business’s primary processes and core business Data management concerns include data accuracy, data security, data organization, and data access

Key Terms Access security Authentication method Consumer audience Core business Data Data access Data accuracy Data consumer Data query Data security Database Fault-tolerant disk system Information Mirror image Physical security Surface area

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