Type of tasks in Informatica:

Tasks are used to create workflows and worklets. Tasks are designed in workflow manager and represent an executable set of actions. Which shows the run time behavior of ETL process. There are several types of tasks available.

1.Session Task

• It is used to run the mapping by using set of instructions.

2.Command task

• Allows to execute operating system command
• In unix we can specify one or more unix commands or a shell script.
• In windows we can specify one or more dos commands or batch files.

3.Decision Task 

• It allows to define own condition that determines the execution of the workflow.
• Integration service evaluates the decision condition specified in a decision task and returns true or false.
• Predefined variable called $Decision_task_name.condition

4.Event Wait/Raise Task

• Event Raise Task: Event Raise task raises the event while running the workflow. It represents the location of a user-defined event. 
• Event Wait Task: The Event Wait task waits for an event to occur.
• There are two types of event

                           Predefined event: A predefined event  is a file-watch event.
                           User defined event: A user defined event is a sequence of tasks in the workflow.

• When all the tasks in the branch from the start task to the Event raise task complete, the Event raise task triggers the event. The Event wait task waits for the Event-Raise task to trigger the event before continuing with the rest of the tasks in its branch. 

5.Assignment task

• It allows to assign a value to a user-defined workflow variable.

6.Timer 

• It allows to set the time between the tasks to set dependencies in the workflow properly.

                            Absolute time: We can specify the time to start a particular task.

                            Relative time: Instruct the integration service to wait for specified period of time                                  after timer starts.

7.Email Tasks

• Send Email during workflow.
• Email addresses, a subject line and the email message text can be defined. When called from within a Session task, the message text can contain variable session-related metadata.

8.Control Task

• It is used to stop or abort the workflow.

Fact Tables in Data Warehouse:

Fact Table in Data Warehouse:

Fact Table:The fact table that contains numerical values of what we measure. There are different types of fact tables are there.

Additive Fact:

 Additive fact is the fact that can be summed up through all the dimensions in the fact table. Sales fact is the example for additive fact.

Semi Additive Fact:

 Semi additive fact is the fact that can be summed up some of the dimensions in the fact table.
Non Additive Fact:

 Non additive fact is the fact that can not be summed for any dimension in the fact table.
Fact less Fact table:

 It is a fact table which will have keys from various dimensions but will not have any facts/measures in it.
Cumulative Fact: 

It is a fact which will store the data over a period of time.
Snap shot: 

It is a fact which will store the data at a point of time.