CREATE TABLE table_30586 ("Stage" FLOAT, "Winner" TEXT, "General classification" TEXT, "Points classification" TEXT, "Mountains classification" TEXT, "Young rider classification" TEXT)

Who was the young rider classification when Alessandro Petacchi won?
SELECT "Young rider classification" FROM table_30586 WHERE "Winner" = 'Alessandro Petacchi'
SELECT "Young rider classification" FROM "table_30586" WHERE "Winner" = 'Alessandro Petacchi'