Table: Students

Sid Sname

$1$ Roy

$2$ John

$3$ Roy

Table : Performance

Sid Class Marks

$\backslash$table$[[1,$Math,$80],[1,$ENG,$70],[2,$Math,$75],[3,$ENG,$80],[2,$Phys$,65],[3,$Math,$80]]$

Consider the relational database above. How many rows will be returned by the following SQL query?

SELECT S$.$Sname, sum$($P$.$Marks$)$

FROM Students S$,$ Performance P

WHERE S$.$ sid $=$ P$.$sid

GROUP BY S$.$ Sname

The query basically joins the two tables on sid, then groups records by Sname, and the $n$ sums up the Marks for each group.

$1$

$6$

$2$

$3$