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

Find the name of the user who gives the most reviews.
SELECT T1.name FROM useracct AS T1 JOIN review AS T2 ON T1.u_id = T2.u_id GROUP BY T2.u_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T1"."name" FROM "useracct" "T1" JOIN "review" "T2" ON "T1"."u_id" = "T2"."u_id" GROUP BY "T2"."u_id" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY