备份PostgreSQL数据库

0. 若1提示`Peer authentication failed for user`, 修改`pg_hba.conf`这一行:
/etc/postgresql/9.5/main/pg_hba.conf

```
local   all             all                                     peer
```

-->

```
local   all             all                                     password
```

https://dba.stackexchange.com/questions/51342/cant-backup-a-postgres-database-fatal-peer-authentication-failed-for-user-po

1. pg_dump命令进行备份:

```bash
pg_dump database_name --username=user > postgres.bak
```

https://www.postgresql.org/docs/9.5/static/backup-dump.html

2. 验证正确备份:

备份的内容为文本格式. 可用`less` `nano`分块查看内容是否正确(比如搜索表名/数据实例).

3. 压缩. 设置密码.

4. 若0, 恢复修改的部分.