Being able to have a config file for your packages is one of the huge improvements in SSIS over DTS. However, it’s a little hidden and the Books Online are absolutely no help here, which is unusual because they are pretty good on most stuff.
If you want to add an XML config file you need to go to the top toolbar and choose SSIS -> Package Configurations… and then choose Add to create a new config file. If it’s not already selected you’ll have to choose “Enable Package Configurations” first.
Then you can choose what you want to add to the configurations – variables and connections are the two most popular ones. Then it will create and XML file in the destination you specify with the configurations you’ve chosen. You can edit them in a text file or have multiple versions that you can swap out as you choose, or specify at runtime which config file to use.
For a good walkthrough, you can visit: http://www.sqlis.com/default.aspx?26.
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