Saturday, June 07, 2014

What is Data Flow Task in SSIS?

The Data Flow Task is the pumping mechanism that moves data from source to destination. However, in the Case of SSIS, you have much more control of what happens from start to finish. In fact, you have a set of out of - the box transformation components that you snap together to clean and manipulate the data while it is in the data pipeline.

One confusing thing for new SSIS developers is that once you drag and drop a Data Flow Task in the
Control Flow, it spawns a new Data Flow design surface with its own new tab in the BIDS user interface.
Each Data Flow Task has its own design surface that you can access by double - clicking the Data Flow Task or by clicking the Data Flow tab and selecting Data Flow Task from the drop - down list. Just as the Controller Flow handles the main workflow of the package, the Data Flow handles the transformation of data. Almost anything that manipulates data falls into the Data Flow category.

As data moves through each step of the Data Flow, the data changes, based on what the transform does.
For Example new column is derived using the Derived Column Transform, and that new column is then available to subsequent transformations or to the destination.

Part of : SSIS Interview Questions and Answers

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