Table schema:
CREATE TABLE settlements (claim_id VARCHAR, settlement_amount INTEGER); CREATE TABLE claims (Effective_Date VARCHAR, claim_id VARCHAR)

Question: What is the effective date of the claim that has the largest amount of total settlement?
SQL: SELECT t1.Effective_Date FROM claims AS t1 JOIN settlements AS t2 ON t1.claim_id = t2.claim_id GROUP BY t1.claim_id ORDER BY SUM(t2.settlement_amount) DESC LIMIT 1