Optimize the following SQL query on the Company Database to find names of employees earning over $30,000 per year, names of projects on which they work more than 12 hours per week, among projects that are located in Houston. Select E.lname, E.fname, P.pname, W.hours From project P, employee E, works_on W Where E.ssn = W.ssn and W.pno = P.pno and P.plocation = 'Houston' and W.hours > 12 and E.salary > 30000 Start with an initial query tree generated by the parser that uses left associativity for joins. Show the query tree after each major step of the algorithm. Show the query execution plan of the optimized query.