对组合列创建统计信息
--检查表结构select * from scott.emp where 1=2;--创建虚拟列 会输出虚拟列名select dbms_stats.create_extended_stats('scott','emp','(empno,JOB)') from dual;select * from dba_tab_cols where column_name like 'SYS_STU%';--查看列名select * from dba_tab_cols a where a.column_name='SYS_STU9D8L7V4NR#823O9R1EKCA6C';--查看列组合的统计信息select * from dba_stat_extensions where extension_name='SYS_STU9D8L7V4NR#823O9R1EKCA6C';--对组合列收集直方图，则可以如下所示：exec dbms_stats.gather_table_stats('scott','emp',method_opt=>'for columns (empno,JOB) size AUTO');