Database.upsert() Lock Errors: The Silent Failure Pattern
When Database.upsert() encounters UNABLE_TO_LOCK_ROW, the error appears in UpsertResult objects — not as an exception. Without explicit handling, lock contention silently drops records.
When Database.upsert() encounters UNABLE_TO_LOCK_ROW, the error appears in UpsertResult objects — not as an exception. Without explicit handling, lock contention silently drops records.