What is the largest claim amount?
select max(amount_claimed) from claim_headers
What was the policy for this?
select * from claim_headers as t1 join policies as t2 on t1.policy_id = t2.policy_id where t1.amount_claimed = (select max(amount_claimed) from claim_headers)
What about for the smallest payment amount instead?
select * from claim_headers as t1 join policies as t2 on t1.policy_id = t2.policy_id where t1.amount_piad = (select min(amount_piad) from claim_headers)
Who owned this policy?
select t3.customer_details from claim_headers as t1 join policies as t2 on t1.policy_id = t2.policy_id join customers as t3 on t2.customer_id = t3.customer_id where t1.amount_piad = (select min(amount_piad) from claim_headers)