However, there are cases where such streaming is not feasible e.g. if we need to compute some statistics or a column widths while printing a table in the terminal. In such situation, we must read the whole relation and only then generate the output. - But we should still be able to do streaming on the relations level e.i. if there are more relation, we always hold only one of them in the memory. + But we should still be able to do streaming on the relations level i.e. if there are more relation, we always hold only one of them in the memory.