A data warehouse is an organized collection of integrated subject-oriented databases designed to aid decision support. It supports business reporting and data mining by providing a consolidated view of cleaned and organized corporate data. Key considerations in data warehouse design include being subject oriented, integrated, time-variant, nonvolatile, summarized, not normalized, including metadata, and being near real-time or tight-time. Data is loaded into the warehouse through extraction, transformation, and loading processes from sources like operational data, specialized applications, and external syndicated data.

1. Nandini Patil
Assistant Professor
Godutai Engg. College,kalaburagi
Data Warehousing

2. Introduction
 Data warehouse is an organized collection of
intergrated, subject-oriented databases designed
to aid decision support function.
 DW supports business reporting & data mining
activities.
 DW enables a consolidated view of corporate
data, all cleaned & organized.

3. Design considerations for DW
 Subject oriented
 Integrated
 Time-variant
 Nonvolatile
 Summarized
 Not normalized
 Metadata
 Near Real-time and /or Tight-time

4. DW development approaches

5. DW Architecture

6. Data Sources
 Operational data
 Specialized applications
 External syndicated data

7. Data loading processes
Data is loaded in DW with ETL process
 Extraction
 Transformation
 Loading

8. Data warehouse design

9. DW access
 OLAP
 Dashboarding system
 Ad-hoc queries
 Data mining