$1.(10$ points$)$

When a user $($or application$)$ submits a SQL query to a relational DBMS$,$ the SQL query

takes the form of a string. Through a series of steps, the DBMS translates this string

into a logical query plan. In this exercise, we practice manually translating two simple

SQL queries into logical query plans.

Consider relations R$($a$,$b$,$c$),$ S$($d$,$e$,$f$),$ and T$($g$,$h$,$i$).$

$($a$)(5$ points$)$ Write a Relational Algebra expression in the form of a logical query plan

that is equivalent to the SQL query below.

SELECT R$.$a$,$ R$.$b$,$ R$.$c$,$ S$.$e$,$ S$.$f$,$ T$.$h

FROM R$,$ S$,$ T

WHERE R$.$c $=$ S$.$d

AND S$.$f$=$T$.$g

AND T$.$i$=$R$.$a

AND R$.$b $>10$

AND S$.$e $=3$