1. SAP transaction RSA3 Enter the Data source Name
Can turn on debugging, if needed
Enter the expected number of rows to extract for testing
Enter the target logical system name
Select execute the run the test extraction

2. Verifying test results
Check number of records selected, please note that this indicates the maximum number of rows selected or requested (see previous screen shot). Please choose the number based on what you are expecting to test this extraction process.
Click on the display list to see actual data extracted