学习目标

掌握openGauss数据库的逻辑备份和恢复技术。

课程学习

1、创建环境

--创建逻辑备份的存储目录
omm@modb:~$ mkdir /var/lib/opengauss/backup
--创建备份恢复用户，需要具有super或者sysadmin权限
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# create user  test IDENTIFIED BY 'huawei@1234' sysadmin ;
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
--创建恢复测试数据库testdb
mm=# CREATE TABLESPACE test_tbs RELATIVE LOCATION 'tablespace/test_tbs1';
CREATE TABLESPACE
omm=# CREATE DATABASE testdb WITH TABLESPACE = test_tbs;

CREATE DATABASE
--在omm数据库上，创建测试表test1、test2：
omm@modb:~$ gsql -d omm    -c "\dt"
                         List of relations
 Schema | Name  | Type  | Owner |             Storage              
--------+-------+-------+-------+----------------------------------
 public | test1 | table | omm   | {orientation=row,compression=no}
 public | test2 | table | omm   | {orientation=row,compression=no}
(2 rows)

2、逻辑备份和恢复案例1（sql格式）
逻辑备份，使用gs_dump备份数据库，生成sql文件
–使用test用户，备份数据库omm：

omm@modb:~$ gs_dump -U test -W huawei@1234  omm -F p -f /var/lib/opengauss/backup/backup.sql
gs_dump[port='5432'][omm][2022-12-13 22:57:18]: The total objects number is 413.
gs_dump[port='5432'][omm][2022-12-13 22:57:18]: [100.00%] 413 objects have been dumped.
gs_dump[port='5432'][omm][2022-12-13 22:57:18]: dump database omm successfully
gs_dump[port='5432'][omm][2022-12-13 22:57:18]: total time: 1510  ms
逻辑恢复：
 
--使用用户test，执行用gs_dump生成的sql脚本，将数据恢复到testdb数据库中：
omm@modb:~$ gsql -d testdb   -U test  -W huawei@1234  -f /var/lib/opengauss/backup/backup.sql
SET
SET
SET
SET
SET
SET
CREATE SCHEMA
ALTER SCHEMA
SET
SET
SET
CREATE TABLE
ALTER TABLE
CREATE TABLE
ALTER TABLE
REVOKE
REVOKE
GRANT
GRANT
total time: 17  ms

恢复验证：

--验证数据库omm的备份已经被恢复到数据库testdb：
--源库（备份的数据库）：
omm@modb:~$ gsql -d omm    -c "\dt"
                         List of relations
 Schema | Name  | Type  | Owner |             Storage              
--------+-------+-------+-------+----------------------------------
 public | test1 | table | omm   | {orientation=row,compression=no}
 public | test2 | table | omm   | {orientation=row,compression=no}
(2 rows)
--新库（恢复的数据库）：
omm@modb:~$ gsql -d testdb   -U test   -W huawei@1234 -c "\dt"
                         List of relations
 Schema | Name  | Type  | Owner |             Storage              
--------+-------+-------+-------+----------------------------------
 public | test1 | table | omm   | {orientation=row,compression=no}
 public | test2 | table | omm   | {orientation=row,compression=no}
(2 rows)

3、openGauss数据库逻辑备份和恢复案例2（dump格式）
逻辑备份：使用gs_dump备份数据库，生成归档格式的备份文件

omm=# CREATE TABLE test3(col int);
omm=# CREATE TABLE
  CREATE TABLE test4(col int);
CREATE TABLE
omm=# \q
omm@modb:~$ gs_dump -U test -W huawei@1234  omm -F p -f /var/lib/opengauss/backup/backup.dump
gs_dump[port='5432'][omm][2022-12-13 23:01:46]: The total objects number is 417.
gs_dump[port='5432'][omm][2022-12-13 23:01:46]: [100.00%] 417 objects have been dumped.
gs_dump[port='5432'][omm][2022-12-13 23:01:46]: dump database omm successfully
gs_dump[port='5432'][omm][2022-12-13 23:01:46]: total time: 1554  ms

逻辑恢复：

SET
SET
SET
SET
SET
SET
gsql:/var/lib/opengauss/backup/backup.dump:16: ERROR:  schema "test" already exists
ALTER SCHEMA
SET
SET
SET
gsql:/var/lib/opengauss/backup/backup.dump:34: ERROR:  relation "test1" already exists in schema "public"
DETAIL:  creating new table with existing name in the same schema
ALTER TABLE
gsql:/var/lib/opengauss/backup/backup.dump:46: ERROR:  relation "test2" already exists in schema "public"
DETAIL:  creating new table with existing name in the same schema
ALTER TABLE
CREATE TABLE
ALTER TABLE
CREATE TABLE
ALTER TABLE
REVOKE
REVOKE
GRANT
GRANT
total time: 23  ms

恢复验证：

omm@modb:~$ gsql -d omm    -c "\dt"
                         List of relations
 Schema | Name  | Type  | Owner |             Storage              
--------+-------+-------+-------+----------------------------------
 public | test1 | table | omm   | {orientation=row,compression=no}
 public | test2 | table | omm   | {orientation=row,compression=no}
 public | test3 | table | omm   | {orientation=row,compression=no}
 public | test4 | table | omm   | {orientation=row,compression=no}
(4 rows)

omm@modb:~$ gsql -d testdb   -U test   -W huawei@1234 -c "\dt"
 public | test3 | table | omm   | {orientation=row,compression=no}
 public | test4 | table | omm   | {orientation=row,compression=no}
(4 rows)

                         List of relations
 Schema | Name  | Type  | Owner |             Storage              
--------+-------+-------+-------+----------------------------------
 public | test1 | table | omm   | {orientation=row,compression=no}
 public | test2 | table | omm   | {orientation=row,compression=no}

学习总结

今天主要是学习opengauss中备份与恢复，逻辑备份与逻辑恢复，备份陈dmp文件与恢复验证，命令还是容易记住，适合入门。