Informatica ETL programs
Informatica ETL programs designed in one of the client applications (Designer or Workflow Manager) and are responsible for the whole ETL process execution.
In Informatica there are a few important objects definitions:
Mapping - developed in Designer, it logically defines the ETL process. Mappings read data from the sources, apply transformation logic to the data and write transformed data to targets.
Transformations are elements of a mapping which generate, modify or pass the data. Transformations are linked together with links through ports (input and output) within a mapping.
There are two groups of transformations: Passive - where the number of rows entering and exiting the transformation are the same (f.ex. Expression, Source Qualifier); Active - number of output rows may not be the same as input rows (f.ex. Aggregator).
Examples of transformations: Source qualifier, expression, filter, sorter, aggregator, joiner, lookup, update strategy, router, transaction control, union.
Task - designed in Workflow Manager, is an executable set of actions, functions or commands. A sequence of tasks defines the runtime behavior of an ETL process.
Example: Session task runs a mapping, Command tasks executes a shell script, Email task sends an email.
Workflow - designed in Workflow Manager, it is a collection of tasks that descibe runtime ETL processes. Tasks can be linked sequentially or concurrently and can also depend on the completion status of previous tasks.
Each linked icon represents a task.
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