What is the average salary paid by team Boston Red Stockings?
select avg(t1.salary) from salary as t1 join team as t2 on t1.team_id = t2.team_id_br where t2.name = 'Boston red Stockings'
How about the average salary paid in 2010?
select avg(t1.salary) from salary as t1 join team as t2 on t1.team_id = t2.team_id_br where t2.name = 'Boston red Stockings' and t1.year = 2010
What is the total salary in this year?
select sum(t1.salary) from salary as t1 join team as t2 on t1.team_id = t2.team_id_br where t2.name = 'Boston red Stockings' and t1.year = 2010