Suppose that a relation factory$($ID$,$ name, street, postcode$)$ contains $800$ tuples. Each tuple is comprised of a header $(24$ bytes$)$ and four attributes: ID $(5$ bytes$),$ name $(10$ bytes$),$ street $(20$ bytes$)$ and postcode $(6$ bytes$).$ The size of each disc block is $1024$ bytes and the size of the header of each disc block size $24$ bytes.

$($i$)$ How many blocks would be required to store the whole of this relation?

$(3$ marks$)$

$($ii$)$ How many blocks would be required to store a projection that does not include the attribute street?

$(3$ marks$)$

$($iii$)$ Explain why such a projection could be used to optimise a query whose results do not include data for the attribute street.