Success use oracle_fdw create oracle foreign table in PostgreSQL

sqlplus /nolog
conn digoal/digoal_123
create table tbl_oracle_fdw (id int,firstname varchar2(32),lastname varchar2(32),crt_time date);
# 插入测试数据
insert into tbl_oracle_fdw values(1,'zhou','digoal',sysdate);
insert into tbl_oracle_fdw values(2,'周','德哥',sysdate);
commit;

psql -h 127.0.0.1 digoal postgres
digoal=# create server ora foreign data wrapper oracle_fdw options (dbserver '//172.16.x.xxx:1521/digoal');
# 下面options使用的是oracle数据库的用户名和密码。
digoal=# create user mapping for digoal server ora options (user 'digoal',password 'digoal_123');
# 下面options使用的是oracle的信息，plan_costs如果为true，需要ORACLE用户有查询v$SQL的权限，后面会有解释。
digoal=# create FOREIGN table tbl_oracle_fdw (id int,firstname varchar(32),lastname varchar(32),crt_time timestamp without time zone) server ora options (table 'tbl_oracle_fdw',schema 'digoal',plan_costs 'true');
# 把这个FOREIGN表赋予给digoal的ALL权限。
digoal=# grant all on tbl_oracle_fdw to digoal;
# 进入digoal用户查询。
digoal=> \c digoal digoal
# 这里报错了，原因是用于连接ORACLE的ORACLE用户digoal没有读取v$sql的权限。
digoal=> select * from tbl_oracle_fdw ;
ERROR:  no SELECT privilege on V$SQL in the remote database
DETAIL:  ORA-00942: table or view does not exist
# 到ORACLE给予digoal用户读取v$SQL的权限
sqlplus "/ as sysdba"
grant select_catalog_role to digoal;

digoal=> select * from tbl_oracle_fdw ;
ERROR:  no SELECT privilege on V$SQL in the remote database
DETAIL:  ORA-00942: table or view does not exist

\c digoal postgres
digoal=# select oracle_close_connections();

\c digoal digoal
digoal=> select * FROM tbl_oracle_fdw;
 id | firstname | lastname |      crt_time       
----+-----------+----------+---------------------
  1 | zhou      | digoal   | 2011-09-15 10:55:32
  2 | 周        | 德哥     | 2011-09-15 11:18:41
(2 rows)

digoal=> delete FROM tbl_oracle_fdw;
WARNING:  column number 0 of foreign table "tbl_oracle_fdw" does not exist in foreign Oracle table, will be replaced by NULL
ERROR:  cannot change foreign table "tbl_oracle_fdw"