Business Intelligence Lecture 2
Development of Data Warehouse Systems
Data Warehouse is a copy of transaction data
specifically structured for query and analysis.
The differences in design and structure:
Operational database Data Warehouse
Structure: highly integrated (more complex than Structure: collection of star schemas (each
any star schema) representing independent entity)
Purpose: both for queries and updating Purpose: for queries only
What is important at the beginning of data warehouse design?
Understanding:
1. The problems the client faces in their business
2. The question the client wants to answer, related to their business (E.g. Which product
is the best-selling? What profit can I expect from the sale of individual products?)
Identification of Business Processes:
Gather user requirements by interviewing clients about their business
Most achieved by conducting surveys and interviewing clients.
Questions like ‘Describe this specific part of your business’ rather than ‘What do you
want?’
Mapping business processes to dimensions
Map business processes to dimension tables, prioritizing based on importance.
Example:
Topic/
Process
, Monitoring the efficiency of studying at the faculty or studying fees income
of the faculty.
Dimensions
Time, Teacher, Course etc.
Facts
Total number of points a student has in the course
Number of points from pre-exam assignments for the course etc.
Logical and Dimensional Model of DW System
Most common levels of schema design in Data Warehouse
1. Conceptual schema
Represents business needs at a high level using ERD or UML.
Design techniques: Entity-Relationships Diagram (ERD) or UML Class diagrams
2. Logical schema
Between the conceptual schema and the physical implementation of the database, specifying
details like data types, keys and constraints.
Design techniques: Entity-Relationships Diagram (ERD) of UML Class diagrams
3. Physical schema
Real implementation of database onto specific DBMS, includes table indexing, storage
optimization, table structure etc.
Design techniques, DBMS-dependent.
4. Dimensional schema
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller iuk. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.21. You're not tied to anything after your purchase.
