Succeeding with Technology Database Systems Basic Data Management Concepts Organizing Data in a...

Succeeding with Technology

Database Systems

Basic Data Management Concepts Organizing Data in a Database Database Management Systems Using Database Systems in Organizations Database Trends Managing Databases

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Chapter 7


The Value of Databases

Databases and Database Management Systems (DBMS) transform large quantities of data into specific and valuable information for accomplishing some goal.


Database Management System (DBMS)

A DBMS consists of a group of programs that manipulate the database and provide an interface between the database and the user or the database and application programs.

Front End

DATABASE

Back End

DBMS

SecureAccess


File or Table

Database

A collection of data organized to meet user’s needs.

Records (Entities)

Field(Attribute)


Database Fields

Fields are set to hold specific types of data.


Database

A Database is a

collection of files/tables


Database Hierarchy


Keys and Primary Key

Key: A field in a record that is used to identify the record

Primary key: A field that uniquely identifies a recordA primary key field prevents duplicate

records from occurring in a table.


Primary Keys

Which field would act as the best primary key?Which field would act as the best primary key?


Primary Keys


Primary Key


Simple but Restrictive DBMS


The Database Approach to Data Management


7.2

Organizing Data in a Database

• Relational Model• Data Analysis

Key Terms


The Relational Model

In a relational database, tables are linked (related) through common fields.


Relation Types One-to-many

Most typical Makes use of primary key

One-to-one Many-to-many


Data Analysis

Data analysis is a process that involves evaluating data to identify problems with the content of a database.Consider what would happen if

CardNumber were not a primary key, and two or more customers had the same CardNumber.

Data Integrity refers to the accuracy of the data in a database.

GIGO, or Garbage In Garbage Out, refers to the fact that inaccurate data entered in a database will result in inaccurate information produced from the database.


7.3

Database Management Systems

• Data Integrity• GIGO• Schema• Data Dictionary• SQL

Key Terms


Creating a Database

A schema is an outline of the logical and physical structure of the data and relationships among the data in the database.


Creating a Database

A data dictionary provides a detailed description of all data used in the database.


Database Strengths

Data can be sifted, sorted and queried through the use of data manipulation languages.

The power of a database and DBMS lies in the user’s ability to manipulate the data to turn up useful information.


Data Manipulation Language

A Data Manipulation Language (DML) is a specific language provided with the DBMS that allows people and other database users to access, modify, and make queries about data contained in the database, and to generate reports.

Structured Query Language (SQL): The most popular DML. SELECT * FROM EMPLOYEE WHERE JOB_CLASSIFICATION = ‘C2”


7.4

Using Database Systems in Organizations

• Data Warehouse• Data Mining

Key Terms


The data deluge… The Machinery Moves on:

Moore’s law: processing “capacity” doubles every 18 months : CPU, cache, memory

It’s more aggressive cousin: Disk storage “capacity” doubles every 9 months

The Demand is exploding:Every business is an eBusinessScientific Instruments and Moore’s lawGovernment

The Internet – the ubiquity of the Web The Talent Shortage


Data Stores Data Warehouse: A database that holds

important information from a variety of sources.

Data Mart: A small data warehouse, often developed for a specific person or purpose.

Data Mining: the process of extracting information from a data warehouse.“Connecting the dots”


Databases & Data Warehouses

Operational Databases


What Is a Hypercube?

Create multi-dimensional “cubes” of information that summarize transactional data across a variety of dimensions.

OLAP vs. OLTP


What is Data Mining?

Finding interesting structure in data Structure: refers to statistical patterns, predictive models,

hidden relationships Interesting: ?

Examples of tasks addressed by Data MiningPredictive Modeling (classification, regression)Segmentation (Data Clustering )Affinity (Summarization)

relations between fields, associations, visualization An Example


Data Mining and Databases

Many interesting analysis queries are difficult to state precisely

Examples:which records represent fraudulent transactions?which households are likely to prefer a Ford over a Toyota?Who’s a good credit risk in my customer DB?

Yet database contains the information good/bad customer, profitabilitydid/did not respond to mailout/survey/...


Example: market basket Transactions

{Bread, Milk}

{Bread, Diapers, Beer, Eggs}

{Milk, Diapers, Beer, Cola}

{Bread, Milk, Diapers, Beer}

{Bread, Milk, Diapers, Cola}

What pattern can you see?


A more systematic approach: a “Decision Tree”

All 1615 patients

Split # 1: Age

“terminal node”Systolic BP


Visualization is Important

Factory food example from this week’s New York Times


The myths…

Companies have built up some large and impressive data warehouses

Data mining is pervasive nowadaysLarge corporations know how to do itThere are tools and applications that discover

valuable information in enterprise databases


The truths… Data is a shambles,

most data mining efforts end up not benefiting from existing data infra-structure

Corporations care a lot about data, and are obsessed with customer behavior and understanding it

They talk a lot about it… An extremely small number of businesses are

successfully mining data The successful efforts are “one-of”, “lucky strikes”

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