如何备份和恢复一个PostgreSQL数据库？

Question

大师 我需要备份和恢复一个PostgreSQL数据库。 我的操作系统版本是Ubuntu的14.04 64位，而PostgreSQL是：

gid: ~/works $ pg_config --version 
PostgreSQL 9.3.15 

我用pg_dump的备份数据库：

gid: ~/works $ pg_dump -U db_name_user -F t db_name > db_name.tar 

我尝试使用pg_restore的恢复数据库并获取失败：

gid: ~/works $ pg_restore -U db_name_user -F t -d db_name db_name.tar 

pg_restore: [archiver (db)] Error while PROCESSING TOC: 
pg_restore: [archiver (db)] Error from TOC entry 3621; 0 0 COMMENT EXTENSION plpgsql 
pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of extension plpgsql 
Command was: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language'; 

pg_restore: WARNING: no privileges could be revoked for "public" 
pg_restore: WARNING: no privileges could be revoked for "public" 
pg_restore: WARNING: no privileges were granted for "public" 
pg_restore: WARNING: no privileges were granted for "public" 
WARNING: errors ignored on restore: 1 

我不知道这是什么意思？ 如何备份和恢复PostgreSQL数据库？

非常感谢。

------------------------ update 1 -------------------- ----

即使我补充说：“--no所有者”选项时的pg_dump和pg_restore的，我还是得到了同样的错误消息：

gid:~/works $ pg_restore -U db_name_user -O -Ft -d db_name db_name.tar 
pg_restore: [archiver (db)] Error while PROCESSING TOC: 
pg_restore: [archiver (db)] Error from TOC entry 3621; 0 0 COMMENT EXTENSION plpgsql 
pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of extension plpgsql 
    Command was: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language'; 

pg_restore: WARNING: no privileges could be revoked for "public" 
pg_restore: WARNING: no privileges could be revoked for "public" 
pg_restore: WARNING: no privileges were granted for "public" 
pg_restore: WARNING: no privileges were granted for "public" 
WARNING: errors ignored on restore: 1 

Answer 1

您可以发表评论的语言忽略错误 - 它不会影响你的代码。 也可以考虑不使用所有者来避免这种警告。但请记住，所有者将成为您在pg_restore上连接的用户，而不是原来的用户。请阅读文档： https://www.postgresql.org/docs/current/static/app-pgrestore.html：

-O

--no-owner Do not output commands to set ownership of objects to match the original database. By default, pg_restore issues ALTER OWNER or SET SESSION AUTHORIZATION statements to set ownership of created schema elements. These statements will fail unless the initial connection to the database is made by a superuser (or the same user that owns all of the objects in the script). With -O, any user name can be used for the initial connection, and this user will own all the created objects.