Databases

The Fundamentals

Understanding InformationUnderstanding Information

• The opening statement says it all;

“ Information is powerful. Information is useful in telling an organization how its current

operations are performing and estimating and strategizing how future operations might

perform”

Data & Information

• We covered this before, way back in chapter 1!

• but it is worth going over 1 more time….

• Data are raw facts that describe characteristics of an event.

• Characteristics of a sales event could be the date, item number, and name.

• Data are raw facts that describe characteristics of an event.

• Characteristics of a sales event could be the date, item number, and name.

Information is data converted into meaningful and useful contextInformation is data converted into meaningful and useful context

Purpose of a Database

• The purpose of a database is to keep track of things that involve more than one theme

An Excel Spreadsheet is useful for keeping track of things as well: But not of things that require more than one theme

Example DB with more than 1 theme

A DB however can manage multiple Theme

What is a DB?

• A database is a self-describing collection of integrated records.

• A byte is a character of data.

• Bytes are grouped into columns, such as Student Number and Student Name.

• Columns are also called fields.

• Columns or fields, in turn, are grouped into rows, which are also called records.

• There is a hierarchy of data elements.

• A database is a collection of tables plus relationships among the rows in those tables, plus special data, called metadata.

• Metadata describes the structure of the database.

Figure 4-3 Student Table (also called File)

Information Granularity• Why is metadata

important?

• Well, when organizations address a business issue they must be able to obtain and analyze all relevant information to make the best decision

• Information we know now comes at different levels. Transactional and analytical….

• This information can be parsed down to extreme details, granularities….

• Information granularity then refers to the extent of detail within the information.

• Information we know now comes at different levels. Transactional and analytical….

• This information can be parsed down to extreme details, granularities….

• Information granularity then refers to the extent of detail within the information.

• Information is created and processed by information levels– Individual– Department– Enterprise

• Information is created and processed by information levels– Individual– Department– Enterprise

• Information comes in a variety of formats– Documents– Presentations– Spreadsheets– Database

• Information comes in a variety of formats– Documents– Presentations– Spreadsheets– Database

• Information comes in granularities• Detail (fine):

individual reports

• Summary: departmental

• Aggregate (Coarse): Across company reporting

High Quality InformationAccuracy Are all values correct? Is name spelt

correctly or $ amount right.

Completeness Are any values missing? Does address include state and zip code?

Consistency Is aggregate or summary information in agreement with detailed information? Example, do all total fields equal the true total of individual fields?

Uniqueness Is each transaction, entity, and event represented only once in the information? Are their duplicate customers?

Timeliness Is information current with respect to the business requirements? Is data updated weekly, daily, or hourly?

Quality information for Decision-Making

Quality information for Decision-Making

• Business decisions are only as good as the quality of information used to make decisions.

• Issues that affect quality information include;

1. Missing information2. Incomplete

information3. Duplicate information4. Wrong information5. Inaccurate information

1. Missing information2. Incomplete

information3. Duplicate information4. Wrong information5. Inaccurate information

How do our systems collect poor data?

• Customers intentionally enter inaccurate information to protect their privacy

• Information from different systems can have different entry standards

• Call center operators enter abbreviated or erroneous information to save time

• Third party and external information contains inconsistencies, inaccuracies, and errors….

Database Fundamentals• Although it should be

obvious, organizations must manage their information properly

• To do this an organization must;

• Although it should be obvious, organizations must manage their information properly

• To do this an organization must;

1. Determine what information it requires

2. Acquire that information

3. Organize the information in a meaningful fashion

4. Assure the information’s quality

5. Provide software tools so that employees throughout the organization can access the information they require

1. Determine what information it requires

2. Acquire that information

3. Organize the information in a meaningful fashion

4. Assure the information’s quality

5. Provide software tools so that employees throughout the organization can access the information they require

DBMS

• Database maintains information about various types of objects, events, people, and places

• Database management system is software through which users and application programs interact with a database

Database AdvantagesIncreased Flexibility Needs to be able to handle changes

quickly; It also needs to be able to allow users to use information in the many different ways they may need to

Increased Scalability & Performance Manages large masses of information and large numbers of users in ways non-technical solutions could not!

Reduced Redundancy Keeps organizations from storing the same information in multiple places

Increased Integrity Is a measure of the quality of information. Integrity constraints are rules that help ensure the quality of information

Increased Security Managed with passwords and levels of authorizations

Data Warehouses & Data Marts

• How can a organization with multiple store fronts spread out across several states share information to better manage;

– Inventory?– Labor budgets on actual number of guests per hour?– Better understand actual costs of foods and use of

ingredients?

• How can a organization with multiple store fronts spread out across several states share information to better manage;

– Inventory?– Labor budgets on actual number of guests per hour?– Better understand actual costs of foods and use of

ingredients?

Data Warehouses

• A data warehouse is a logical collection of information—gathered from many different operational databases

• Databases support business analysis activities and decision-making tasks

Model of a typical Data WarehouseModel of a typical Data Warehouse

ETLETL

• Data warehouses compiles information from internal databases or transactional/ operational databases and external databases through extraction, transformation, and loading (ETL)

• The process begins a 2nd time when the data warehouse then sends subsets of the information to data marts

Data Marts• Why send information

to a data mart?

• Data marts contain a subset of data warehouse information

• The ultimate goal with any integrated information system--whether it be a data mart or a data warehouse--is to provide consistent, accurate data about the organization to the users.

• Department-focused data marts have only the information that group needs.

• Each department has its own specific uses for a data mart, which often ignore the information needs of other areas.

• The ultimate goal with any integrated information system--whether it be a data mart or a data warehouse--is to provide consistent, accurate data about the organization to the users.

• Department-focused data marts have only the information that group needs.

• Each department has its own specific uses for a data mart, which often ignore the information needs of other areas.

Business Intelligence

• BI: is information that people use to support their decision-making efforts

• In order to do this BI should allow organizations to;

• BI: is information that people use to support their decision-making efforts

• In order to do this BI should allow organizations to;

– Collect information

– Discern patterns & meaning in the information

– Respond to resultant information

Gaining sustainable competitive advantage with BI• BI is now considered the

art of sifting through large amounts of data, extracting information, and turning that information into actionable knowledge

• To make this happen principal BI enablers need to be in place

Technology Technology enables even the smallest of companies to compute and monitor business metrics

People “business intelligence for the masses” takes the BI out of the hands of analysts and into the hands of employees closest to the customer

Culture Set by executives and managers. Best way to encourage BI is to measure the performance of key indicators