一、学习目标
进一步学习表空间与数据库对象的关系，了解oid的含义。
二、课程学习
1.创建表空间、多个数据库和用户
--进入数据库omm，创建表空间、测试数据库
su - omm
gsql -r
drop DATABASE IF EXISTS musicdb;
drop DATABASE IF EXISTS musicdb1;
drop DATABASE IF EXISTS musicdb2;
drop DATABASE IF EXISTS musicdb3;
drop tablespace IF EXISTS music_tbs;
drop tablespace IF EXISTS ds_location1;
CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE DATABASE musicdb WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb1 WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb2 WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb3 WITH TABLESPACE = music_tbs;
--执行下面的SQL语句，创建用户user1 ：
drop user IF EXISTS user1;
CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
--授予user1数据库系统的SYSADMIN权限：
ALTER USER user1 SYSADMIN;
实训环境示例：
root@modb:~# su - omm
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 DATABASE IF EXISTS musicdb;
NOTICE: database "musicdb" does not exist, skipping
DROP DATABASE
omm=# drop DATABASE IF EXISTS musicdb1;
NOTICE: database "musicdb1" does not exist, skipping
DROP DATABASE
omm=# drop DATABASE IF EXISTS musicdb2;
NOTICE: database "musicdb2" does not exist, skipping
DROP DATABASE
omm=# drop DATABASE IF EXISTS musicdb3;
NOTICE: database "musicdb3" does not exist, skipping
DROP DATABASE
omm=# drop tablespace IF EXISTS music_tbs;
NOTICE: Tablespace "music_tbs" does not exist, skipping.
DROP TABLESPACE
omm=# drop tablespace IF EXISTS ds_location1;
NOTICE: Tablespace "ds_location1" does not exist, skipping.
DROP TABLESPACE
omm=# CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE TABLESPACE
omm=# CREATE DATABASE musicdb WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE DATABASE musicdb1 WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE DATABASE musicdb2 WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE DATABASE musicdb3 WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=#
omm=# drop user IF EXISTS user1;
NOTICE: role "user1" does not exist, skipping
DROP ROLE
omm=# CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=#
omm=# ALTER USER user1 SYSADMIN;
omm=# ALTER ROLE
omm=# \du
List of roles
Role name | Attributes
| Member of
-----------+------------------------------------------------------------------------
------------------------------------------+-----------
gaussdb | Sysadmin
| {
}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monito
radmin, Operatoradmin, Policyadmin, UseFT | {
}
user1 | Sysadmin
| {
}
omm=#
2.使用sql查看数据库所在的表空间
–查看数据库所在的表空间，可以看到一个表空间可以有多个数据库
select datname,dattablespace,spcname from pg_database d, pg_tablespace t where d.dattablespace=t.oid;
omm=# select datname,dattablespace,spcname from pg_database d, pg_tablespace t where d.dattablespace=t.oid;
datname | dattablespace | spcname
-----------+---------------+------------
template1 | 1663 | pg_default
omm | 1663 | pg_default
musicdb | 16389 | music_tbs
template0 | 1663 | pg_default
musicdb1 | 16389 | music_tbs
musicdb2 | 16389 | music_tbs
musicdb3 | 16389 | music_tbs
postgres | 1663 | pg_default
(8 rows)
omm=#
3.在文件系统中查看表空间中的多个数据库
--查看数据库、表空间的oid
select oid,datname from pg_database;
select oid,* from pg_tablespace ;
select datname,dattablespace,spcname from pg_database d, pg_tablespace t where d.dattablespace=t.oid;
--从文件系统，查看music_tbs表空间oid，可以看到一个表空间可以有多个数据库
cd /var/lib/opengauss/data/pg_tblspc/xxxxx/
cd PG_9.2*
ls
#说明：xxxxx是表空间 music_tbs的oid
omm=# select oid,datname from pg_database;
oid | datname
-------+-----------
1 | template1
16384 | omm
16390 | musicdb
14555 | template0
16391 | musicdb1
16392 | musicdb2
16393 | musicdb3
14560 | postgres
(8 rows)
omm=# select oid,* from pg_tablespace ;
oid | spcname | spcowner | spcacl | spcoptions | spcmaxsize | relative
-------+------------+----------+--------+------------+------------+----------
1663 | pg_default | 10 | | | | f
1664 | pg_global | 10 | | | | f
16389 | music_tbs | 10 | | | | t
(3 rows)
d.dattablespace=t.oid; tablespace,spcname from pg_database d, pg_tablespace t where
datname | dattablespace | spcname
-----------+---------------+------------
template1 | 1663 | pg_default
omm | 1663 | pg_default
musicdb | 16389 | music_tbs
template0 | 1663 | pg_default
musicdb1 | 16389 | music_tbs
musicdb2 | 16389 | music_tbs
musicdb3 | 16389 | music_tbs
postgres | 1663 | pg_default
(8 rows)
omm=# \q
omm@modb:~$ cd /var/lib/opengauss/data/pg_tblspc/16389
omm@modb:/var/lib/opengauss/data/pg_tblspc/16389$ cd PG_9.2_201611171_gaussdb/
omm@modb:/var/lib/opengauss/data/pg_tblspc/16389/PG_9.2_201611171_gaussdb$ ls
16390 16391 16392 16393 pgsql_tmp
omm@modb:/var/lib/opengauss/data/pg_tblspc/16389/PG_9.2_201611171_gaussdb$
三、课后作业
1. 创建表空间newtbs1
CREATE TABLESPACE newtbs1 RELATIVE LOCATION ‘tablespace/test_ts2’;
omm=# CREATE TABLESPACE newtbs1 RELATIVE LOCATION 'tablespace/test_ts2';
CREATE TABLESPACE
omm=# \db
List of tablespaces
Name | Owner | Location
------------+-------+---------------------
music_tbs | omm | tablespace/test_ts1
newtbs1 | omm | tablespace/test_ts2
pg_default | omm |
pg_global | omm |
(4 rows)
omm=#
2. 创建3个数据库newdb1、newdb2、newdb3，默认表空间为newtbs1
CREATE DATABASE newdb1 WITH TABLESPACE = newtbs1;
CREATE DATABASE newdb2 WITH TABLESPACE = newtbs1;
CREATE DATABASE newdb3 WITH TABLESPACE = newtbs1;
omm=# CREATE DATABASE newdb1 WITH TABLESPACE = newtbs1;
CREATE DATABASE
omm=# CREATE DATABASE newdb2 WITH TABLESPACE = newtbs1;
CREATE DATABASE
omm=# CREATE DATABASE newdb3 WITH TABLESPACE = newtbs1;
CREATE DATABASE
omm=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+-------+----------+---------+-------+-------------------
musicdb | omm | UTF8 | C | C |
musicdb1 | omm | UTF8 | C | C |
musicdb2 | omm | UTF8 | C | C |
musicdb3 | omm | UTF8 | C | C |
newdb1 | omm | UTF8 | C | C |
newdb2 | omm | UTF8 | C | C |
newdb3 | omm | UTF8 | C | C |
omm | omm | UTF8 | C | C |
postgres | omm | UTF8 | C | C |
template0 | omm | UTF8 | C | C | =c/omm +
| | | | | omm=CTc/omm
template1 | omm | UTF8 | C | C | =c/omm +
| | | | | omm=CTc/omm
(11 rows)
omm=#
3. 使用sql查看表空间newtbs1上有几个数据库
select oid,datname from pg_database;
select oid,* from pg_tablespace ;
select datname,dattablespace,spcname from pg_database d, pg_tablespace t where d.dattablespace=t.oid;
omm=# select oid,datname from pg_database;
oid | datname
-------+-----------
1 | template1
16384 | omm
16390 | musicdb
14555 | template0
16391 | musicdb1
16392 | musicdb2
16393 | musicdb3
14560 | postgres
16399 | newdb1
16400 | newdb2
16401 | newdb3
(11 rows)
omm=# select oid,* from pg_tablespace ;
oid | spcname | spcowner | spcacl | spcoptions | spcmaxsize | relative
-------+------------+----------+--------+------------+------------+----------
1663 | pg_default | 10 | | | | f
1664 | pg_global | 10 | | | | f
16389 | music_tbs | 10 | | | | t
16398 | newtbs1 | 10 | | | | t
(4 rows)
omm=# select datname,dattablespace,spcname from pg_database d, pg_tablespace t where d.dattablespace=t.oid;
datname | dattablespace | spcname
-----------+---------------+------------
template1 | 1663 | pg_default
omm | 1663 | pg_default
musicdb | 16389 | music_tbs
template0 | 1663 | pg_default
musicdb1 | 16389 | music_tbs
musicdb2 | 16389 | music_tbs
musicdb3 | 16389 | music_tbs
postgres | 1663 | pg_default
newdb1 | 16398 | newtbs1
newdb2 | 16398 | newtbs1
newdb3 | 16398 | newtbs1
(11 rows)omm=#
omm=#
4. 在文件系统中查看表空间newtbs1中的多个数据库
cd /var/lib/opengauss/data/pg_tblspc/16398/
cd PG_9.2_201611171_gaussdb/
ls
omm@modb:~$ cd /var/lib/opengauss/data/pg_tblspc/16398/
omm@modb:/var/lib/opengauss/data/pg_tblspc/16398$ cd PG_9.2_201611171_gaussdb/
omm@modb:/var/lib/opengauss/data/pg_tblspc/16398/PG_9.2_201611171_gaussdb$ ls
16399 16400 16401 pgsql_tmp
omm@modb:/var/lib/opengauss/data/pg_tblspc/16398/PG_9.2_201611171_gaussdb$