Dimensional Models

Dimensional Models

1. Designing Data warehouse

2. Can be used directly by end users

3. OBJECTIVES

   • Database structures easy for end users
   • Optimized query performance

4. ER Model to Dimensional Models

   • Step 1: Classify entities
   • Step 2: Design high-level star schema
   • Step 3: Design detailed fact table
   • Step 4: Design detailed dimension table

5. ER model can be transformed into a dimensional models

   • Subsetting
   • Denormalization
   • Summarization

6. Advanced design

   • Alternative dimensional structures
     • Star
     • Snowflakes
     • Starflakes
   • Slowly changing dimensions
   • Minidimensions
   • Heterogeneous star schemas
   • Dealing with non-hierarchical data

7. Advanced design

   • Alternative dimensional structures
     • Stars
     • Snowflakes
     • Starflakes
   • Slowly changing dimensions
   • Minidimensions
   • Heterogeneous star schema
   • Dealing with non-hierarchical data

8. ER Model to Dimensional

   • Step 1: Classify entities
   • Step 2: Design high-level star schema
   • Step 3: Design detailed fact table
   • Step 4: Design detailed dimension table

9. ER Model can be stransformed into a set of dimensional models

   • Subsetting
   • Denormalization
   • Summarization

Bilder und Dateien der Mindmap