For now while row insert appears, it's possible to select row by indexes that have been processed. But if unique constraint is violated, er need to reject insertion and rollback inserts. In this case we have gap when it's possible to select invalid row.
For now while row insert appears, it's possible to select row by indexes that have been processed. But if unique constraint is violated, er need to reject insertion and rollback inserts. In this case we have gap when it's possible to select invalid row.