openGauss每日一练第 20 天| 学习心得体会

学习心得

本课程我觉得非常重要，备份恢复永远是数据库技术的核心内容

课后作业

1.逻辑备份和恢复案例1:使用sql格式进行备份和恢复omm数据库

root@modb:~# su - omm
omm@modb:~$ mkdir /var/lib/opengauss/backup
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
omm=# create tablespace test_tbs relative location 'tablespace/test_tbs1';
CREATE TABLESPACE
omm=# create database testdb with tablespace=test_tbs;
CREATE DATABASE
omm=# create table test1(i int);
CREATE TABLE
omm=# create table test2(i int);
CREATE TABLE
omm=# \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)

omm=# insert into test1 values(1);   <----------模拟数据插入
omm=# INSERT 0 1
  
omm=# insert into test2 values(2);   <----------模拟数据插入
INSERT 0 1
omm=# exit
omm-# 
omm-# 
omm-# \q
omm@modb:~$ gs_dump -U test -W huawei@1234 omm -F p -f /var/lib/opengauss/backup/backuptest.sql     <----------备份
gs_dump[port='5432'][omm][2022-12-13 20:19:52]: The total objects number is 413.
gs_dump[port='5432'][omm][2022-12-13 20:19:52]: [100.00%] 413 objects have been dumped.
gs_dump[port='5432'][omm][2022-12-13 20:19:52]: dump database omm successfully
gs_dump[port='5432'][omm][2022-12-13 20:19:52]: total time: 1655  ms

omm=# drop table test1;  <--------------------模拟删除数据
DROP TABLE
omm=# \q

omm@modb:~$ gsql -d omm -U test  -W huawei@1234  -f /var/lib/opengauss/backup/backuptest.sql  <-------恢复
SET
SET
SET
SET
SET
SET
gsql:/var/lib/opengauss/backup/backuptest.sql:16: ERROR:  schema "test" already exists
ALTER SCHEMA
SET
SET
SET
CREATE TABLE
ALTER TABLE
gsql:/var/lib/opengauss/backup/backuptest.sql:46: ERROR:  relation "test2" already exists in schema "public"
DETAIL:  creating new table with existing name in the same schema
ALTER TABLE
REVOKE
REVOKE
GRANT
GRANT
total time: 16  ms
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=# select * from test1;   <-----------------数据已经恢复
 i 
---
 1
(1 row)

2.逻辑备份和恢复案例2:使用dump格式进行备份和恢复omm数据库

omm@modb:~$ gs_dump -U test -W huawei@1234  omm -F p -f /var/lib/opengauss/backup/backup.dump <----------备份
gs_dump[port='5432'][omm][2022-12-13 20:36:55]: The total objects number is 413.
gs_dump[port='5432'][omm][2022-12-13 20:36:55]: [100.00%] 413 objects have been dumped.
gs_dump[port='5432'][omm][2022-12-13 20:36:55]: dump database omm successfully
gs_dump[port='5432'][omm][2022-12-13 20:36:55]: total time: 1708  ms
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=# drop table test2;  <--------------------模拟删除数据
DROP TABLE
omm=# exit
omm-# ^C
omm=# \q
omm@modb:~$ gsql -d omm -U test  -W huawei@1234  -f /var/lib/opengauss/backup/backup.dump <----------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
CREATE TABLE
ALTER TABLE
REVOKE
REVOKE
GRANT
GRANT
total time: 16  ms
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=# select * from test2;
 i 
---
 2
 2
(2 rows)