A Journey to Data Architect ..

 A Data Warehouse is a subject-oriented integrated time-varying non-volatile COLLECTION OF DATA THAT is used PRIMARILY IN ORGANIZATIONAL DECISION MAKING. - Bill Inmon,Building the Data Warehouse 1996 A process of transforming data into information and making it available to users in a timely enough manner to make a difference Forrester Research April 1996 Data Warehouse Architecture     OLTP vs Data Warehouse                            OLTP                Data Warehouse Application Oriented Used to Run Business Detailed Data Current Up to Date Isolated Data Repetitive Access User Specific Performance Sensitive Less Records accessed at a time Read/Update Access No Data Redundancy (Normalization) Subject Oriented Used to Analyze Business Summarized and Refined Snapshot Data Integrated Data Ad-hoc Access Business User Performance Relaxed Large Volumes ...

  Traditional Data Warehouse Concepts A  data warehouse  is any system that collates data from a wide range of sources within an organization. Data warehouses are used as centralized data repositories for analytical and reporting purposes. A traditional data warehouse is located on-site at your offices. You purchase the hardware, the server rooms and hire the staff to run it. They are also called on-premises, on-prem or (grammatically incorrect) on-premise data warehouses. Facts, Dimensions, and Measures The core building blocks of information in a data warehouse are facts, dimensions, and measures. A  fact  is the part of your data that indicates a specific occurrence or transaction. For example, if your business sells flowers, some facts you would see in your data warehouse are: Sold 30 roses in-store for $19.99 Ordered 500 new flower pots from China for $1500 Paid salary of cashier for this month $1000 Several numbers can describe each fact, and we call these...