$2.$ What index would you create to speed this query on a table with no indexes: select $*$ from mytable where fieldA $=$ 'val$1\text{'}$ order by fieldB limit $10?$

$3.$ What index would you create to speed this query on a table with no indexes: select fieldA, min$($fieldC$)$ from mytable where fieldB $=$ 'val$1\text{'}$ group by fieldA?

$4.$ Given this schema:

mytable$1($ fieldIndex$1,$ fieldA $)$

mytable$2($ fieldIndex$2,$ fieldB $($FK to mytable$1),$ fieldC, fieldD $)$

What indexes would you create to speed this query on a table with no indexes: select mytable$1.$fieldA, mytable$2.$fieldD from mytable$1$ join mytable$2$ on mytable$1.$fieldIndex$1=$ mytable$2.$fieldB where mytable$2.$fieldC $=\text{'}$A$\text{'}?$