1.在 oracle 创建表 

create table emp_fdw(empno int,ename varchar(30)); 

insert into emp_fdw values(1,'foo'); insert into emp_fdw values(2,'bar'); 

2.创建连接 

create server ora_jdbc foreign data wrapper jdbc_fdw options( 

drivername 'oracle.jdbc.driver.OracleDriver', 

url 'jdbc:oracle:thin:@//172.16.103.104:1521/orcl', 

querytimeout '100',

 jarfile '/home/vastbase/bin/ojdbc7.jar', 

maxheapsize '200' );

3.新建用户并授权 

create user use_ora_jdbc password 'Bigdata@123'; 

grant usage on foreign server ora_jdbc to use_ora_jdbc; 

4.创建到 oracle 的映射 

create user mapping for use_ora_jdbc server ora_jdbc options(username 'system',password 'root'); 

5.创建需要访问的 oracle 中对应表的结构 

create foreign table emp_fdw_ora(empno int,ename varchar(30)) 

server ora_jdbc options(table 'EMP_FDW'); 

grant all on emp_fdw_ora to use_ora_jdbc; 

6.查看外部表 

c - use_ora_jdbc 

select * from emp_fdw_ora;