chapter 9 database systems
DESCRIPTION
Chapter 9 Database Systems. Courtesy of Chris Pascucci , Shelly/ Vermaat , Joanne Nichols. Database Basics. Database C ollection of data on a specific topic or purpose that is stored for future use. Data is organized so you can access, retrieve, sort, and edit data. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 9 Database Systems
Courtesy of Chris Pascucci, Shelly/Vermaat, Joanne Nichols
2
Database Basics Database
– Collection of data on a specific topic or purpose that is stored for future use.
– Data is organized so you can access, retrieve, sort, and edit data.
Database Management System (DBMS)– Software used to create, use, and manage a database.– Create forms, reports, and queries.
Database System– Comprised of a database, DBMS, and applications.– Applications such as e-commerce and scheduling.– University example: registration applications, financial applications,
etc…
3
Database Basics Data
– Unprocessed items like raw facts, numbers, text, etc…
Information– Data that has been processed in an organized and meaningful way.
A major function of a computer is to process data into information.
4
Database Integrity Data Integrity is maintained when
data is accurate and up-to-date.
Garbage In, Garbage Out (GIGO) – computer phrase that means you
cannot create correct information from incorrect data.
Garbage out
Garbage in
Data integrity is lost
Characteristics of Information
5
Accurate Verifiable Timely
Organized Accessible Useful
Cost-effective
Data dictionary A data dictionary contains data about each
file in the database and each field in those files
6
Validating Data
7
Alphabetic/Numeric check Range check Consistency check
Completeness check Check digit Other checks
8
Database Systems Multiple users can interact with the same database
9
The Hierarchy of Data A database contains files, files contain records, and records
contain fields. Database
– A collection of integrated and related files.
Files– A collection of related records.
Records– A collection of related fields.
Fields– A collection of characters that describe some aspect of an object.– A single piece of information like a name, number, city, state, etc…
10
The Hierarchy of Data
Hierarchy of Data
11
12
Data File Example
key field
records fields
2 East Penn Drive99 Tenth Street33 Timmons Place
33099 Clark Street
54 Lucy Court
Address
PittsboroCarmelCincinnati
Montgomery
Shelbyville
City
INRuizAdelbert3928INElena4872
OHDrakeLouella3876
ALMurrayShannon2928
INBrewerMilton2295
StateLast NameFirst NameMember ID
Gupta
13
Database Management Systems
File Maintenance
14
Adding Records
Modifying Records
Deleting Records
15
Benefits of Using a DBMS Enter data quickly and easily. Organize records in different and useful ways. Locate records quickly. Eliminate redundant data. Create queries for specific data. Create reports.
16
DBMS
17
Database Approach to Data Management
Database Approach– Many applications and users can share data in a database.– Secures data so only authorized users can access it.
• Access privileges (none, read-only, full-update)• Principle of least privilege
– Provides means to backup data.– Requires a DBMS.
File Processing System Approach– Each department/area within an organization has its own set of files.– Data redundancy - same data stored in multiple files.– Isolated data - data stored in files at various physical locations -
difficult to access.
18
Benefits of Using a Database Approach
File Processing vs DBMS
19
20
Database Management Creating and implementing the right database system
involves:– Determining how data is stored and retrieved.– How people will see and use the database.– How the database will be created and maintained.– How reports and documents will be generated.
Types of Databases Relational Databases (most commonly used) Object-Oriented Databases Multi-Dimensional Databases (used for data warehouses) Others…
21
22
Relational Databases A relational database stores data in a table that consists of
rows and columns.
Most common type of database used for payroll, inventory, ordering, and other business-related functions.
Also stores data relationships, which are connections within data.
23
Relational Databases
24
Object-Oriented Databases An object-oriented database stores data in objects.
An object is an item that contains data, as well as actions that read and process the data.
Mainly used for multimedia databases (video, audio, graphics), CAD (computer aided design) , and Web databases.
25
Multi-Dimensional Databases A multi-dimensional database stores data in dimensions.
Multiple dimensions, also called hypercube, allow users to analyze any view of data.
Can consolidate data much faster than relational database.
26
Multi-Dimensional Databases
27
Large-Scale Databases Data-Warehouse
– Huge database that stores and manages massive amounts of data.– Holds important information from a variety of sources.– Usually a subset of multiple database.
Data Mart– Smaller version of a data warehouse.– Often developed for a specific purpose.
• Examples: sales department, inventory and shipping department, finance department, upper level management, and so on. Regional operating centers might each have their own data mart that contributes to the master data warehouse
28
Large-Scale Databases Data-Mining
– A technique used to extract information from a data warehouse or a data mart.
– Sort through huge amounts of data to find patterns and establish relationships among the data.
Business Intelligence– Business use of data mining can help increase efficiency, reduce
costs, or increase profits.– Identifies trends.– Identifies patterns in customer behaviors.
29
Example of Data Mining Wal-Mart captures point-of-sale transactions from over 2,900
stores in 6 countries and continuously transmits this data to its massive 500+ terabyte data warehouse. 1 Terabyte = 1 trillion characters (bytes)
Can determine what products are selling well or poorly in which regions.
Database is refreshed every hour.
Wal-Mart allows more than 3,500 suppliers to access data on their products and perform data analyses.
These suppliers use this data to identify customer buying patterns at the store display level. They use this information to manage local store inventory and identify new merchandising opportunities.
30
Data Mining Some concerns regarding Data-Mining
– DARPA (Defense Advanced Research Projects Agency ) developed project TIA (Terrorism Information Awareness).
• Main goal of TIA is to preemptively uncover and disrupt terrorist attacks.• TIA helps U.S. government monitor daily transactions such as, credit card
transactions, airline tickets, rental car, passport, driver’s license, etc…– Medical Information
• Prescription reminders sent from a pharmacy require access to certain personal information.
• Profiling patients based on factors such as, age, gender, disease, etc…– Clinicians must make patients aware of how their information may be used.
– Limitations:• Data mining tools are not self-sufficient applications and require trained specialists
to analyze the information generated by these tools.• Patterns and connections that are found depend on “Real World” circumstances
that may be casual and not necessarily be a threat.
31
Databases How are databases important to us?
Shop for products or
services
Buy or sell stocks
Search for a job
Make airline reservations
Register for college classes
Check semester grades
32
Databases in ActionNCIC – National Crime Information Center FBI’s huge database created in 1967 under J. Edgar Hoover. Over 15 million active records in 19 files. Makes available a variety of records for law enforcement and security
purposes. Information in this database assists in:
– Apprehending fugitives– Locating missing persons– Locating and returning stolen property
http://www.fbi.gov/about-us/cjis/ncic
33
Databases in ActionNational DNA Database Originally intended for sex offenders – has since been extended to
include almost any criminal offender. FBI uses this database to store missing persons DNA. Stores DNA crime scenes samples. Used to ID unidentified human remains. US has over 9 million records in CODIS (Combined DNA index system) – largest DNA DB in the world!
34
Databases in ActionNational Security Agency (NSA) Database “largest database ever assembled in the world”, from unnamed source in
the NSA. Contains hundreds of billions of records of telephone calls. Existence of this database and the NSA program that compiled it was
unknown to the general public until USA TODAY broke the story in May 2006.
Records and saves all phone calls ever made and all telecommunications via a “black room” called “Room 641A”.
Supercomputers analyze all data in their database to find certain flags.
– Terrorist chatter