The following problems are based$$on the following query:

SELECT $$ EMP$\_$LNAME, EMP$\_$FNAME, EMP$\_$DOB, YEAR$($EMP$\_$DOB$)$ AS YEAR

FROM $$ EMPLOYEE

WHERE $$ YEAR$($EMP$\_$DOB$)=1966$;

$$

$3.$ What is the likely data sparsity of the EMP$\_$DOB column?

$$

$4.$ Should you create an index on EMP$\_$DOB? Why or why not?

$5.$ What type of database I$/$O operations will likely be used by the query?