8.1 Describe the roles and purposes of data warehouses and data marts in an organization.
8.2 Compare the multidimensional nature of data warehouses (and data marts) with the two-dimensional nature of databases.
8.3 Identify the importance of ensuring the cleanliness of information throughout an organization.
8.4 Explain the relationship between business intelligence and a data warehouse.
1.History of Data Warehousing
⇾Data warehouses extend the transformation of data into information because variety number of databases.
⇢In the 1990's executives became less concerned with the day-to-day business operations and more concerned with overall business functions.
➟The data warehouse provided the ability to support decision making without disrupting the day-to-day operations.
➨The day-to-day activities such as customer service and billing.
⇨Cannot handle too much information at one time.
➔Databases become increases and they realize they want system that more systematic so that WAREHOUSE exist.
2.Data Warehouse Fundamentals
➪i)Data warehouse - a logical collection of information from many different operational databases to supports business analysis activities and decision-making tasks(link to the business intelligence).The primary purpose of a data warehouse is to aggregate information throughout an organization into a single repository for decision-making purposes.
➟ii)Extraction,transformation and loading (ETL)- process that extracts information from internal & external databases,transforms the information using a common set of enterprise definitions ,and loads the information into a data warehouse.
-Not all databases put at warehouse ,it keep internal and external database. Example :External for industries they key in data of competitors.
➣iii)Data mart - contains a subset of data warehouse information.
➥data warehouse contain a lot of information
3.Multidimensional Analysis and Data Mining
➤Databases contain information in a series of two-dimensional tables. Databases and warehouse are totally different.
➤Data warehouse and data mart ,information is multidimensional it contains layers of columns and rows.
-Dimension is a particular attribute of information.
➤Cube- common term for the representation of multidimensional information.
-Dimension is a particular attribute of information.
➤Cube- common term for the representation of multidimensional information.
⟹i) Cube A - It have variety of product from different store and different promotions .There have all the information so that we can see everything.
⟹ii)Cube B - It for promotion II ,for all products, and all store.
⟹iii)Cube C- It is data mart where as it only for certain information that we want.
➤Data mining - process of analyzing data to extract information not offered by the raw data alone.
*To perform data mining users need data-mining tools:
⇨Data-mining tool -uses a variety of techniques to find patterns and relationships in large volumes of information and infers rules that predict future behavior and guide decision making.
4.Information cleansing or scrubbing
→An organization must maintain high-quality data in the data warehouse.
⇝Help upper do good decision making.
⇨Information cleansing or scrubbing - process that weeds out and fixes or discards inconsistent, incorrect or incomplete information.
↝ Contact Information in an Operational System
↠ Standardizing customer name from Operational Systems ( it can predict redundancy so can cleansing or scrubbing).
↝Information cleansing activities
⇨Accurate & complete information
5.Business Intelligence
➨Business Intelligence -information that people use to support their decision-making efforts (help upper level do decision making).
➨Principle BI enablers include:
-i)Technology
-ii)People
-iii)Culture
➠i)Technology -helps a lot ,nowadays even the smallest company with BI software can do sophisticated analyses .Technology is the most significant enabler of business intelligence.
➠ii)People- Without people no want can operate technology .It also can performance and use technology.
➦iii)Culture - A key responsibility of executives is to shape and manage corporate culture.Top level must have knowledge about technology and must adapt culture.

































