For the three join strategies $($nest$-$loop, sort$-$merge, and hash join$),$ discuss whether each strategy can be used to implement left outer join and full outer join. If you make changes to a strategy to make it applicable, focus your discussion on your proposed changes.Note: Inner join of R and S returns only matching tuples. Left outer join returns the union of inner join results and unmatched tuples in R $($padded with NULL as values for attributes from S$).$ Full outer join returns the union of inner join results, unmatched tuples in R$,$ and unmatched tuples in S $($padded with NULLs as values for attributes from the other relation$).$