DWH Life cycle

DWH is a process of building a data warehouse

1) Requirement gathering

  • It is done by business analysts, Onsite technical lead and client
  • In  this  phase  a  Business  Analyst  prepares  business  requirement specification(BRS)Document
  • 80% of requirement collection takes place at clients place and it takes 3-4 months for collecting the requirements

2) Analysis:

  • After collecting the requirements data modeler starts identifying dimensions, facts & aggregation depending on the requirements
  • An ETL Lead & BA create ETL specification document which contains how each target table to be populated from source

3) System Requirement Specification (SRS)

  • After collection of onsite knowledge transfer offshore team will prepare the SRS
  • A SRS document includes software,hardware,operating system requirements

4) Data Modeling

  • It’s a process of designing the database by fulfilling the use requirements
  • A data modeler is responsible for creating DWH/Data marts with the following kinds of schema

Star schema
Snowflake schema

5) ETL Development

  • Designing ETL applications to fulfill the specifications documents which are prepared in analysis phase

6) ETL Code review:

Code review will be done by developer

The following activities take place

  • Check the naming standards
  • Check the business logic
  • Check the mapping of source to target

7) Peer Review:

Code will be reviewed by a team member

  • Validation of code but not data

8) ETL Testing:

Following tests will be carried out for each ETL Application

  • Unit testing
  • Business Functionality testing
  • Performance testing
  • User acceptance testing

9) Report development environment:

  • Design the reports to fulfill report requirement templates/Report data workbook(RDW)

10) Deployment:

  • Process of migrating the ETL Code & Reports to a pre production environment for stabilization
  • It is also known as pilot phase/stabilization phase

11) Production Environment/Go live:

  • An active/working environment


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