查看Oracle 表结构的创建和最后修改时间

SELECT a.owner, a.table_name, created, last_ddl_time
  FROM dba_tables a, SYS.dba_objects b
WHERE a.tablespace_name = 'USERS'
   AND a.owner = b.owner
   AND a.table_name = b.object_name
   AND object_type = 'TABLE'