CREATE TABLE review (a_id DECIMAL, u_id DECIMAL, i_id DECIMAL, rating DECIMAL, rank DECIMAL)
CREATE TABLE useracct (u_id DECIMAL, name TEXT)
CREATE TABLE item (i_id DECIMAL, title TEXT)
CREATE TABLE trust (source_u_id DECIMAL, target_u_id DECIMAL, trust DECIMAL)

Find the name of the source user with the highest average trust score.
SELECT T1.name FROM useracct AS T1 JOIN trust AS T2 ON T1.u_id = T2.source_u_id GROUP BY T2.source_u_id ORDER BY AVG(trust) DESC LIMIT 1
SELECT "T1"."name" FROM "useracct" AS "T1" JOIN "trust" AS "T2" ON "T1"."u_id" = "T2"."source_u_id" GROUP BY "T2"."source_u_id" ORDER BY AVG("trust") DESC NULLS LAST LIMIT 1