Data warehouse Concepts - Day 2 i

What is datawarehouse?

A data warehouse is built on relational database that is designed for query and analysis rather than for transaction processing. It usually contains historical data derived from transaction data, but it can include data from other sources. It separates analysis workload from transaction workload and enables an organization to consolidate data from several sources.
In addition to a relational database, a data warehouse environment includes an extraction, transportation, transformation, and loading (ETL) solution, an online analytical processing (OLAP) engine

Characteristics of a data warehouse

Subject Oriented
Integrated
Nonvolatile
Time Variant

Different Types of Data

Metadata
Dimension data
Fact Data
Aggregated Data

Data warehouse Architectures



Dimension Modeling


Identify a Business Process
Identify Grain
Identify elements which describe the process (Dimensions)
Identify elements which measure process(facts)10