This lesson covers the basics of the Data Flow Task. Section III comprises chapters covering the sources, destinations, and transformations in detail. However, this lesson gives you the tools to get started creating a Data Flow and understanding the purpose of it.
The Data Flow Task is used to transfer data from a source to a destination and can transform the data as needed. The source can be any of several different types such as a flat file or database and can contain millions of rows of data. The Data Flow Task is capable of handling large amounts of data. The destination can be of several types also.
The Data Flow Task can be used to extract data from a database and write to a flat file location or move the data from a flat file to a database. This capability allows you to receive files from outside sources and write this data to your database. You can also use the Data Flow Task to move data from one database to another database.
The transforms that exist in the Data Flow allow you to make changes to the data as you move it from a source to a destination. For example, if you are receiving flat files from a vendor and the data is not formatted correctly, say, the Social Security numbers need to have dashes, you can fix that before writing it to a database. Fixing things like that prior to writing to your database prevents you from running updates on your database later.
And these transforms are faster in SSIS. SSIS performs the transforms in memory, ...