Consider the following statement：
SQL> EXECUTE DBMS_STATS.GATHER_SHEMA_STATS （-
2> ownname => ‘OE’， -
3> estimate_percent => DBMS_STATS.AUTO_SAMPLE_SIZE， -
4> method opt => ‘for all columns size AUTO’）；
What is the effect of ‘for all columns size AUTO’ of the METHOD_OPT option？（）
