Unfortunately I face situations looking like timed out or not responding gui.
Import classic import (100'000 records) ~ 5 seconds

MERGE import to empty table (100'000 records) ~15 seconds

MERGE delete 250 records (of the 100'000 records) no end reached after more than 15 minutes*

*When I checked the database next day, the 250 records were gone (total records 99750 – total physical records 100'000)!?.
Any idea what is going wrong here?