I used external loader fastload in informatica to load the teradata table. The source has 5 million records and after executing the workflow, I see that 10 records are missing in the target. I don't understand what happened to those 10 records. If the records were rejected, I can see that in rejects or else it would reflect in the session log. What should I do?
I have never worked with Informatica, so I am not sure what those logs do for you. But since you didn't find anything there, maybe you should query the two error tables that you create at the beginning of the mload to see if your missing 10 rows were written to the error tables.
You say you selected FASTLOAD? FastLoad always quietly eliminates totally duplicate rows. If you really need to load duplicate rows to a MULTISET table you should use some other method, e.g. MultiLoad.