Data WareHouse

Data WareHouse

1. Is a pool of data produced to support decision making

   • also a repository of current an historial data of potential interest to managers throughout the organization
   • Data are structured to be available in a form ready for analytical processing activities
     • For example: OLAP, data mining, querying, reporting.

2. Is a subject-oriented, integrated, time-variant, nonvolatile collection of data in support of management's decision-making process

3. In the 2000s

   • Consolidation of DW/BI industry
   • Data warehouse appliances emerged
   • Business intelligence appliances emerged
   • Data mining and predictive modeling

4. Fundamental characteristics

   • Subject oriented
     • Data are organized by detailed subject, such as sales, products, or customers, containing only information relevant for decision support.
   • Integrated
     • Data warehouses must place data from different sources into a consistent format.
   • Time variant
     • The data do not necessarily provide current status, they detect trends, deviations, and long-ten relationships for forecasting and comparisons, leading to decision making.
   • Nonvolatile
     • After data are entered into a data warehouse, users cannot change or update the data. Changes are recorded as new data
   • Web based
     • Data warehouses are typically designed to provide an efficient computing environment for web-based applications
   • Relation/muldimensional
     • A data warehouse uses either a relational structure or a multidimensional structure.
   • client/server
     • A data warehouse uses the client/server architecture to provide easy access for end users.
   • Real time
     • Newer data warehouses provide real-time, or active, data-access and analysis capabilities
   • include metadata
     • A data warehouse contains metadata about how the data are organized and how to effectively use them

5. 3 types of warehouses

   • Data Marts
     • Is usually smaller and focuses on a particular subject or department
       • Is a subset of a data warehouse, typically consisting of a single subject area.
     • Operational Data Store (ODS)
       • Provides a fairly recent form of customer information file (CIF)
         • Is often used as an interim staging area for a data warehouse
     • Enterprise Data WareHouses (EDW)
       • Is a large-scale data warehouse that is used across the enterprise for decision support