Database Reference
In-Depth Information
Data flows are made up of other subtasks. In this way, data flows are similar to control flows in that they both
contain various SSIS tasks; however, data flow tasks are specialized for transferring data from one location to
another.
A data flow task can be edited either by double-clicking the task while working in the Control Flow tab or by
navigating to the Data Flow tab at the top of the designer window.
Figure
7-10
illustrates the three categories of data flow tasks that are used to configure a data flow: Sources,
Transformations, and Destinations.
Figure 7-10.
Commonly used data flow tasks
In Figure
7-10
, we have outlined four transformation tasks that you regularly see in SISS data flow tasks.
These transformations are found under the Common collection in the SSIS Toolbox. Many other transformations
exist, but these are commonly used in ETL processing. These four transformations perform the same actions as
the SQL programming statements detailed in Chapter 6, just not as efficiently.
Each data flow needs one or more data sources, zero or more transformations, and one or more destinations.
Both a data source and a data destination are required for data to “flow” from one place to another, but SSIS
transformations are not required. Let's review each of these categories of tasks.
