学习目标

掌握openGauss数据库的逻辑备份和恢复技术。

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

--为逻辑备份准备环境，创建逻辑备份的存储目录：
root@modb:~# su - omm
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 'aabb@123' sysadmin;
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE

--创建恢复测试数据库testdb
omm=# 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=# create table test1(col int);
CREATE TABLE
omm=# create table test2(col int);
CREATE TABLE
omm=# \q

--查看数据
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)

--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  omm -F p -f /var/lib/opengauss/backup/backup.sql
Password: 
gs_dump[port='5432'][omm][2022-12-13 10:08:34]: The total objects number is 413.
gs_dump[port='5432'][omm][2022-12-13 10:08:34]: [100.00%] 413 objects have been dumped.
gs_dump[port='5432'][omm][2022-12-13 10:08:34]: dump database omm successfully
gs_dump[port='5432'][omm][2022-12-13 10:08:34]: total time: 7775  ms

--查看SQL备份的数据文件：
omm@modb:~$ cat /var/lib/opengauss/backup/backup.sql 
--
-- openGauss database dump
--
SET statement_timeout = 0;
SET xmloption = content;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SET check_function_bodies = false;
SET client_min_messages = warning;
--
-- Name: test; Type: SCHEMA; Schema: -; Owner: test
--
CREATE SCHEMA test;
ALTER SCHEMA test OWNER TO test;
SET search_path = public;
SET default_tablespace = '';

SET default_with_oids = false;
--
-- Name: test1; Type: TABLE; Schema: public; Owner: omm; Tablespace: 
--
CREATE TABLE test1 (
    col integer
)
WITH (orientation=row, compression=no);
ALTER TABLE public.test1 OWNER TO omm;
--
-- Name: test2; Type: TABLE; Schema: public; Owner: omm; Tablespace: 
--
CREATE TABLE test2 (
    col integer
)
WITH (orientation=row, compression=no);
ALTER TABLE public.test2 OWNER TO omm;
--
-- Data for Name: test1; Type: TABLE DATA; Schema: public; Owner: omm
--
COPY test1 (col) FROM stdin;
\.
;
--
-- Data for Name: test2; Type: TABLE DATA; Schema: public; Owner: omm
--
COPY test2 (col) FROM stdin;
\.
;
--
-- Name: public; Type: ACL; Schema: -; Owner: omm
--
REVOKE ALL ON SCHEMA public FROM PUBLIC;
REVOKE ALL ON SCHEMA public FROM omm;
GRANT CREATE,USAGE ON SCHEMA public TO omm;
GRANT USAGE ON SCHEMA public TO PUBLIC;
--
-- openGauss database dump complete
--


--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 -f /var/lib/opengauss/backup/backup.sql 
Password for user test: 
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: 19  ms

--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 -c "\dt"
Password for user test: 
                         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2:使用dump格式进行备份和恢复omm数据库

--逻辑备份：使用gs_dump备份数据库，生成归档格式的备份文件
--创建测试数据
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 table test3(col int);
CREATE TABLE
omm=# create table test4(col int);
CREATE TABLE
omm=# \q

--使用test用户，备份omm数据库，生成归档格式的备份文件:
omm@modb:~$ gs_dump -U test omm -F p -f /var/lib/opengauss/backup/backup.dump
Password: 
gs_dump[port='5432'][omm][2022-12-13 10:11:08]: The total objects number is 417.
gs_dump[port='5432'][omm][2022-12-13 10:11:08]: [100.00%] 417 objects have been dumped.
gs_dump[port='5432'][omm][2022-12-13 10:11:08]: dump database omm successfully
gs_dump[port='5432'][omm][2022-12-13 10:11:08]: total time: 4218  ms

--使用gs_dump生成的归档文件恢复数据库
omm@modb:~$ gsql -d testdb -U test -f /var/lib/opengauss/backup/backup.dump 
Password for user test: 
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: 18  ms
 
 --源库（备份的数据库）：
omm@modb:~$ gsql -d omm -c "\dt"
(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}
 public | test3 | table | omm   | {orientation=row,compression=no}
 public | test4 | table | omm   | {orientation=row,compression=no}
 
--新库（恢复的数据库）：
omm@modb:~$ gsql -d testdb -U test -c "\dt"
Password for user test: 
(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}
 public | test3 | table | omm   | {orientation=row,compression=no}
 public | test4 | table | omm   | {orientation=row,compression=no}