Relations $R$ and $T$ have to be joined together $(R|><mi\; id="EditorElement\_6644028">|</mi><mi\; id="EditorElement\_6644030">T</mi><mi\; id="EditorElement\_6644032">)</mi>$ on a common attribute $x.$

We know the number of blocks in each relation: $B_R=2000$ and $B_T=20.$ Mark all

correct statements below.

$($a$)$ The most efficient order to execute a block nested loop join is to have $R$ as the

outer relation.

$($b$)$ The most efficient order to execute a block nested loop join is to have $T$ as the

outer relation.

$($c$)$ If $R$ and $T$ are already sorted a sort$-$merge join complexity can be reduced to

$2020$ pages.

$($d$)$ If we have enough blocks in$-$memory to fit $R$ and $T$ then the total block nested

join complexity can be reduced to $2020$ pages.