This page provides information on how to get the .castextraction file.
Here this page is explained by taking an example for Sybase, however this is valid for Oracle, MS SQL server, DB 2 as well.
1. CAST Extraction for Sybase
With 1st option i.e. CAST Extraction for Sybase: The .castextraction is inside the sources.CastSourcePackage of delivery folder.To get this you need to unzip it and it is inside the Meta Folder
For example : sources.CastSourcePackage is placed at :
After Unzip, It is can at:
With 2nd option i.e. Reuse existing CAST delivery output: The .castextarction is not created in sources.CastSourcePackage and hence not in Delivery folder.
You can retrieve these .castextraction files on the machine where you have run the Extraction/delivery processing.