CREATE TABLE table_204_843 (id NUMBER, "volume" NUMBER, "year" CLOB, "names" CLOB, "articles" NUMBER, "pages" NUMBER, "images" NUMBER, "maps" NUMBER, "number of copies" NUMBER)

which volume had the most maps ?
SELECT "volume" FROM table_204_843 ORDER BY "maps" DESC LIMIT 1
SELECT "volume" FROM "table_204_843" ORDER BY "maps" DESC FETCH FIRST 1 ROWS ONLY