The relational algebra query :
\(\begin{array}{l} \rho_{Tempside}\left( {\left( {{\pi _{sid,bid}}Reserve} \right) \div \left( {{\pi _{bid}}Boats} \right)} \right)\\ {\pi _{sname}}\left( {TempsideāSailors} \right) \end{array}\)
1
Find the name of sailors who has reserved some boats
2
Find the name of sailors who has reserved all boats
3
Find the name of sailors reserved red boat
4
None of these
5
Question Not Attempted