同义词是对象的一本别名同义词并不占用任何实际的存储空间只是oracle的数据字典中保存其定义描述在使用同义词时oracle会将其翻译为对应对象的名称
同义词分类公共同义词私有同义词
创建同义词create [public] synonym synonym_name for schema_objectCREATE [PUBLIC] SYNONYM synonym_name FOR schema_object注创建同义词时所对应的模式对象不必存在
删除同义词DROP [PUBLIC] SYNONYM synonym_name
创建同义词必须的权限conn / as sysdba grant create synonym to scottgrant create public synonym to scott
优点a用户去访问b用户的b表aselect * from bb创建同义词为a则查询很方便aselect * from a