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DW-1: Introduction to Data Warehousing
Overview
What is Database
What Is Data Warehousing
Data Marts and Data Warehouses
The Data Warehousing Process
Data in a Data Warehouse
What Is Database
Before
Program = Algorithm + Data Structure
Now
Application (Weblication) = Visual I/F + SQL Query + Database
Database is Integrated Data
from multiple file system data for OLTP
Data Base (From Air Base?), DB, 데이타베이스 , 자료기지 ( 북한 )
Database and Data Model
Computer Representation of Data for efficient understanding and processing
Data Model based on Relationship modeling
Relationship between recordone-to-one(1:1), one-to-many(1:N), many-to-many(N:M)
Hierarhical Model: Hierarchical Relationship, 1:N
Network model: Network like relationship, N:M
Relational Model: Use relation (table) for Relationship
Object-Oriented data model: Complex object modelingSET type, Reference, List
What Is Data Warehousing
Defining Data Warehousing
Operational Systems: A Transactional Solution
Analytical Systems: A Data Warehousing Solution
Comparing Transactional and Data Warehousing Solutions
Defining Data Warehousing
Business Intelligence Database Marketing: Personalized Product
Especially S/W, Cocoon business etc. Electronic Commerce
Data Warehouse: 자료 창고 for OLAP, Data Mining, DSS
Knowledge Management
Data Warehousing: Process to build Data Warehouse
Defining Data Warehousing
A Data Warehouse Is a Database That Contains: Enterprise data Integrated sets of historical data Subject-oriented, consolidated, consistent data Data structured for distribution and querying
A Data Warehousing Solution Is a Process That: Retrieves and transforms data Manages the database Uses tools for building and managing the data warehouse
Operational Systems: A Transactional Solution
Track Individual Events
Used for Real-time Data Entry and Editing
Examples:
Order-tracking applications
Customer service applications
Point-of-sale applications
Service-based sales applications
Banking functions
Analytical Systems: A Data Warehousing Solution
Assist with Strategic Decision Support
Provide Different Levels of Analysis
Allow Users to Navigate to Different Levels of Data
Allow System Searches to Find New Relationships
Examples:
Spreadsheet-based applications
Sales forecasting applications
Comparing Transactional and Data Warehousing Solutions
TransactionalTransactionalsolutionssolutions
TransactionalTransactionalsolutionssolutions
Data warehousingData warehousingsolutionssolutions
Data warehousingData warehousingsolutionssolutions
Update frequencyUpdate frequency Real-timeReal-time PeriodicallyPeriodically
Structured forStructured for Data integrityData integrity Ease in queryingEase in querying
Optimized forOptimized for Transaction performanceTransaction performance Query performanceQuery performance
Data Marts and Data Warehouses
What Is a Data Mart
Moving Data from a Data Warehouse to Data Marts
Moving Data from Data Marts to a Data Warehouse
What Is a Data Mart
What Is a Data Mart A subset of a data warehouse Used in an enterprise Specific to a particular subject or business activity
Why Build Data Marts Faster queries and fewer users Faster deployment time
Integrated Data Marts Ensure consistent data Require advance planning
Moving Data From a Data Warehouse to Data Marts
Advantages Shared fields Common source Distributed processing
Disadvantages Longer time to develop
Customer Customer Service MartService Mart
Sales MartSales Mart
DataDataWarehouseWarehouse Financial MartFinancial Mart
Source 1Source 1Source 1Source 1
Source 2Source 2Source 2Source 2
Source 3Source 3Source 3Source 3
Moving Data from Data Marts to a Data Warehouse
Advantages Simpler and faster to implement Department-specific data Smaller hardware requirements
Disadvantages Data duplication Incompatible data marts
DataDataWarehouseWarehouse
Sales MartSales Mart
Financial MartFinancial Mart
Customer ServiceCustomer ServiceMartMart
Source 1Source 1Source 1Source 1
Source 2Source 2Source 2Source 2
Source 3Source 3Source 3Source 3
The Data Warehousing Process
Basic Elements of the Process
Tools to Manage the Process
Basic Elements of the Process
Data Marts
DataDataWarehouseWarehouse
Source OLTPSystems
Clients
Retrieve DataRetrieve Data Populate Populate Populate Populate Query Query Transform Data Transform Data Data Warehouse Data Warehouse Data Marts Data Marts the Data the Data
11
22
33 44 55
Tools to Manage the Process
SQL Server
Data Transformation Services
SQL Server OLAP Services
Microsoft Repository
Microsoft English Query
PivotTable Service
ETL process
Extraction, Transformation, Loading
Extraction: 추출
Data retrieval from existing data source such as File, Table etc.
Transformation: 변환
Data modification, sorting, calculation etc
Loading: 적재
Bulk, incremental loading from operational DB
Time consuming process: may use special H/W
Data in a Data Warehouse
Data Characteristics
Example of Organizing Data
Data Characteristics
Data characteristicData characteristicData characteristicData characteristic DescriptionDescriptionDescriptionDescription
ConsolidatedConsolidated Enterprise-wideEnterprise-wide
ConsistentConsistent Within the data warehouseWithin the data warehouse
Subject-orientedSubject-oriented Organized to user perspectiveOrganized to user perspective
HistoricalHistorical Snapshots over timeSnapshots over time
Read-onlyRead-only Cannot updateCannot update
SummarizedSummarized To appropriate level of detailTo appropriate level of detail
Example of Organizing Data
Southeast RegionTotal
City
Miami
Tampa
Atlanta
Savannah
Columbia
Monthly Southeast Regional Sales Report - May 1999
State
FL
FL
FL Totals
GA
GA
GA Totals
SC
SC Totals
Units Sold
2,500
2,750
5,250
3,200
1,725
4,925
1,900
1,900
12,075
Sales $
$12,850
$14,135
$26,985
$16,800
$ 9,143
$25,943
$ 9,595
$ 9,595
$62,473
Data Warehouse Schema Example: Star schema
A Example of Cube Browsing
1 Fact with 4 Dimension Table-- Sales_Fact, Product, Store, Time, Customer
Drilling Down
Drilling Down to products
Drilling Down
Drilling Down to the lowest level of Customer Dimension
Rolling up
Rolling up
Review
What Is Data Warehousing
Data Marts and Data Warehouses
The Data Warehousing Process
Data in a Data Warehouse
Data Warehouse will be more popular than DB?
