Data Mining And Business Intelligence (2170715)

BE | Semester-7   Winter-2018 | 03/12/2018

Q3) (c)

Explain three tier data warehouse Architecture in details.

Three tier Data Warehouse Architecture

Find a simpler diagram for understanding at the bottom
  1. Bottom tier :
    • The bottom tier is a warehouse database server that is almost always a relational database system
    • Back-end tools and utilities are used to feed data into the bottom tier from operational databases or other external sources
    • These tools and utilities perform data extraction, cleaning, and transformation, as well as load and refresh functions to update the data warehouse
    • The data are extracted using application program interfaces known as gateways
    • A gateway is supported by the underlying DBMS and allows client programs to generate SQL code to be executed at a server
    • Examples of gateways include ODBC (Open Database Connection) and OLEDB (Open Linking and Embedding for Databases) by Microsoft and JDBC (Java Database Connection
    • This tier also contains a metadata repository, which stores information about the data warehouse and its contents.
  2. Middle tier :
    • The middle tier is an OLAP server that is typically implemented using either
    • A relational OLAP (ROLAP) model, that is, an extended relational DBMS that maps operations on multidimensional data to standard relational operations or
    • A multidimensional OLAP (MOLAP) model, that is, a special-purpose server that directly implements multidimensional data and operations.
  3. Top tier :
    • The top tier is a front-end client layer, which contains query and reporting tools, analysis tools, and/or data mining tools