26-06-2012, 02:15 PM
Information PowerCenter
Information PowerCenter .ppt (Size: 666.5 KB / Downloads: 270)
Data Warehousing
Data warehousing is the entire process of data extraction, transformation, and loading of data to the warehouse and the access of the data by end users and applications
Data Mart
A data mart stores data for a limited number of subject areas, such as marketing and sales data. It is used to support specific applications.
An independent data mart is created directly from source systems.
A dependent data mart is populated from a data warehouse.
Need For ETL Tool
Often performed by COBOL routines (not recommended because of high program maintenance and no automatically generated meta data)
Sometimes source data is copied to the target database using the replication capabilities of standard RDBMS (not recommended because of “dirty data” in the source systems)
Increasing performed by specialized ETL software
Process Flow
Informatica Server moves the data from source to target based on the workflow and metadata stored in the repository.
A workflow is a set of instructions how and when to run the task related to ETL.
Informatica server runs workflow according to the conditional links connecting tasks.
Session is type of workflow task which describes how to move the data between source and target using a mapping.
Mapping is a set of source and target definitions linked by transformation objects that define the rules for data transformation.