Every tried to figure out the exact ETL/ELT process that is running some sql statement from within the database..... good luck with that!
Query Banding is part of Teradata's workload management features BUT can also be simply used to trace exactly what process is executing something.
Even if you don't take advantage of the Teradata workload features, every Informatica session that is executed can be determine within Teradata by implementing the query band.
This makes support and performance tuning alot simpler.
The attached guide describes what Teradata Query Banding is and how to implement it with the Informatica.