openGauss每日一练第8天 | openGauss中一个数据库可以存储在多个表空间中

原创宋小宝 2022-12-01

132

一、学习目标

学习表空间与数据库对象的关系。
在musicdb数据库中创建的所有的表，没有指定表空间的名字，因此都创建在数据库默认的表空间music_tbs中，当我们在musicdb数据库中创建表warehouse_t1的时候，明确指定在表空间ds_location1中创建时，这个表会存储在这个指定的表空间。即一个数据库中的对象，可以位于不同的表空间.

二、课程学习

1.连接数据库，准备测试环境

--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;

CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE DATABASE musicdb  WITH TABLESPACE = music_tbs;

--执行下面的SQL语句，创建用户user1：

 CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
 
--授予user1数据库系统的SYSADMIN权限：

ALTER USER user1 SYSADMIN;
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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=# CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE TABLESPACE
omm=# CREATE DATABASE musicdb  WITH TABLESPACE = music_tbs;

CREATE DATABASE
omm=# 
omm=# CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# ALTER USER user1 SYSADMIN;
ALTER ROLE
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2.创建表空间、查看表空间

--执行下面的命令，查看当前表空间：
\db
--创建一个新的名为ds_location1的表空间：
 CREATE TABLESPACE ds_location1 RELATIVE LOCATION 'tablespace/tablespace_1';
--执行下面的命令，查看实例当前有哪些表空间：
\db
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omm=# \db
           List of tablespaces
    Name    | Owner |      Location       
------------+-------+---------------------
 music_tbs  | omm   | tablespace/test_ts1
 pg_default | omm   | 
 pg_global  | omm   | 
(3 rows)

omm=# CREATE TABLESPACE ds_location1 RELATIVE LOCATION 'tablespace/tablespace_1';
CREATE TABLESPACE
omm=# \db
              List of tablespaces
     Name     | Owner |        Location         
--------------+-------+-------------------------
 ds_location1 | omm   | tablespace/tablespace_1
 music_tbs    | omm   | tablespace/test_ts1
 pg_default   | omm   | 
 pg_global    | omm   | 
(4 rows)

omm=# 
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3.使用user1用户，访问musicdb数据库，在表空间ds_location1上创建表warehouse_t1，查看musicdb数据库目前有哪些表：

\c musicdb user1
 create table warehouse_t1 (col1 char(10)) tablespace ds_location1;
select table_catalog, table_schema, table_name, table_type
  from information_schema.tables
   where table_schema not in ('pg_catalog', 'information_schema','dbe_perf');
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musicdb=> \c musicdb user1
Password for user user1: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user1".
musicdb=> create table warehouse_t1 (col1 char(10)) tablespace ds_location1;
CREATE TABLE
musicdb=> select table_catalog, table_schema, table_name, table_type
musicdb->   from information_schema.tables
musicdb->    where table_schema not in ('pg_catalog', 'information_schema','dbe_perf');
 table_catalog |  table_schema   |  table_name  | table_type 
---------------+-----------------+--------------+------------
 musicdb       | db4ai           | snapshot     | BASE TABLE
 musicdb       | dbe_pldeveloper | gs_errors    | BASE TABLE
 musicdb       | dbe_pldeveloper | gs_source    | BASE TABLE
 musicdb       | public          | warehouse_t1 | BASE TABLE
(4 rows)

musicdb=> 
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4.查询表在那个表空间
系统表在默认表空间，非系统表在指定的表空间中（否则在默认表空间）

--建表warehouse_t1指定表空间ds_location1，查看表warehouse_t1所在的表空间：
select * from pg_tables where tablename = 'warehouse_t1';

--创建表warehouse_t12未指定表空间，则在默认表空间（不显示默认表空间名）
create table warehouse_t12 (col1 char(10));
select * from pg_tables where tablename = 'warehouse_t12';
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musicdb=> select * from pg_tables where tablename = 'warehouse_t1';
 schemaname |  tablename   | tableowner |  tablespace  | hasindexes | hasrules | hastriggers | tablecreator |            created            |         last_ddl_time      
   
------------+--------------+------------+--------------+------------+----------+-------------+--------------+-------------------------------+----------------------------
---
 public     | warehouse_t1 | user1      | ds_location1 | f          | f        | f           | user1        | 2022-12-01 11:24:42.613711+08 | 2022-12-01 11:24:42.613711+
08
(1 row)

musicdb=> create table warehouse_t12 (col1 char(10));
CREATE TABLE
musicdb=> select * from pg_tables where tablename = 'warehouse_t12';
 schemaname |   tablename   | tableowner | tablespace | hasindexes | hasrules | hastriggers | tablecreator |            created            |         last_ddl_time       
  
------------+---------------+------------+------------+------------+----------+-------------+--------------+-------------------------------+-----------------------------
--
 public     | warehouse_t12 | user1      |            | f          | f        | f           | user1        | 2022-12-01 11:27:36.858823+08 | 2022-12-01 11:27:36.858823+0
8
(1 row)

musicdb=> 
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6.查看openGuass数据库的默认表空间

select datname,dattablespace,spcname from pg_database d, pg_tablespace t where d.dattablespace=t.oid
复制

musicdb=> 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
 postgres  |          1663 | pg_default
(5 rows)

musicdb=> 
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7.查询数据库的默认表空间上的对象

select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
from pg_class a  
where a.relkind in ('r', 'i')  
and reltablespace='0'  
order by a.relpages desc;
复制

musicdb=> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
musicdb-> from pg_class a  
musicdb-> where a.relkind in ('r', 'i')  
and reltablespace='0'  
musicdb-> musicdb-> order by a.relpages desc;
                    relname                     | relkind | relpages | pg_size_pretty | reltablespace | relowner 
------------------------------------------------+---------+----------+----------------+---------------+----------
 pg_attribute                                   | r       |      184 | 1472 kB        |             0 |       10
 pg_proc                                        | r       |      140 | 1120 kB        |             0 |       10
 pg_depend                                      | r       |       59 | 472 kB         |             0 |       10
 pg_class                                       | r       |       52 | 416 kB         |             0 |       10
 pg_attribute_relid_attnam_index                | i       |       44 | 352 kB         |             0 |       10
 pg_proc_proname_all_args_nsp_index             | i       |       41 | 328 kB         |             0 |       10
 pg_proc_proname_args_nsp_new_index             | i       |       39 | 312 kB         |             0 |       10
 pg_proc_proname_args_nsp_index                 | i       |       39 | 312 kB         |             0 |       10
 pg_rewrite                                     | r       |       37 | 296 kB         |             0 |       10
 pg_description                                 | r       |       31 | 248 kB         |             0 |       10
 pg_attribute_relid_attnum_index                | i       |       30 | 240 kB         |             0 |       10
 pg_depend_depender_index                       | i       |       34 | 272 kB         |             0 |       10
 pg_depend_reference_index                      | i       |       34 | 272 kB         |             0 |       10
 pg_type                                        | r       |       20 | 160 kB         |             0 |       10
 pg_statistic                                   | r       |       19 | 152 kB         |             0 |       10
 pg_operator                                    | r       |       15 | 120 kB         |             0 |       10
 pg_class_relname_nsp_index                     | i       |       14 | 112 kB         |             0 |       10
 pg_proc_oid_index                              | i       |       13 | 104 kB         |             0 |       10
 pg_class_tblspc_relfilenode_index              | i       |       10 | 80 kB          |             0 |       10
 pg_amop                                        | r       |        9 | 72 kB          |             0 |       10
--More-- pg_description_o_c_o_index                     | i       |       16 | 128 kB         |             0 |       10
 pg_class_oid_index                             | i       |        7 | 56 kB          |             0 |       10
 sql_features                                   | r       |        7 | 56 kB          |             0 |       10
 pg_type_typname_nsp_index                      | i       |        7 | 56 kB          |             0 |       10
 pg_index                                       | r       |        7 | 56 kB          |             0 |       10
 pg_amop_fam_strat_index                        | i       |        6 | 48 kB          |             0 |       10
 pg_operator_oprname_l_r_n_index                | i       |        6 | 48 kB          |             0 |       10
 pg_amop_opr_fam_index                          | i       |        6 | 48 kB          |             0 |       10
 pg_amop_oid_index                              | i       |        5 | 40 kB          |             0 |       10
 pg_operator_oid_index                          | i       |        5 | 40 kB          |             0 |       10
 pg_type_oid_index                              | i       |        5 | 40 kB          |             0 |       10
 pg_opclass_am_name_nsp_index                   | i       |        4 | 32 kB          |             0 
...
 gs_column_keys_args                            | r       |        0 | 0 bytes        |             0 |       10
 gs_client_global_keys_args                     | r       |        0 | 0 bytes        |             0 |       10
 gs_client_global_keys                          | r       |        0 | 0 bytes        |             0 |       10
 pg_publication_rel                             | r       |        0 | 0 bytes        |             0 |       10
 gs_matview                                     | r       |        0 | 0 bytes        |             0 |       10
 gs_encrypted_proc                              | r       |        0 | 0 bytes        |             0 |       10
 gs_job_argument                                | r       |        0 | 0 bytes        |             0 |       10
 warehouse_t12                                  | r       |        0 | 0 bytes        |             0 |    16391
 gs_asp                                         | r       |        0 | 0 bytes        |             0 |       10
 gs_matview_dependency                          | r       |        0 | 0 bytes        |             0 |       10
 pg_object                                      | r       |        0 | 8192 bytes     |             0 |       10
 gs_auditing_policy_privileges                  | r       |        0 | 0 bytes        |             0 |       10
 pg_synonym                                     | r       |        0 | 0 bytes        |             0 |       10
(316 rows)
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8.查询表空间ds_location1上的对像

\c musicdb user1
select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
from pg_class a, pg_tablespace tb  
where a.relkind in ('r', 'i')  
and a.reltablespace=tb.oid  
and tb.spcname='ds_location1'  
order by a.relpages desc;
复制

musicdb=> \c musicdb user1
Password for user user1: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user1".
musicdb=> musicdb-> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
musicdb-> from pg_class a, pg_tablespace tb  
where a.relkind in ('r', 'i')  
musicdb-> and a.reltablespace=tb.oid  
musicdb-> and tb.spcname='ds_location1'  
musicdb-> order by a.relpages desc;
   relname    | relkind | relpages | pg_size_pretty | reltablespace | relowner 
--------------+---------+----------+----------------+---------------+----------
 warehouse_t1 | r       |        0 | 0 bytes        |         16396 |    16391
(1 row)

musicdb=> 
复制

三、课后作业

1. 创建表空间newtbs1、ds_location1，查看表空间

create tablespace newtbs1 relative location ‘tablespace/tablespace_2’;
create tablespace ds_location1 relative location ‘tablespace/tablespace_1’;

musicdb=> \db
           List of tablespaces
    Name    | Owner |      Location       
------------+-------+---------------------
 music_tbs  | omm   | tablespace/test_ts1
 pg_default | omm   | 
 pg_global  | omm   | 
(3 rows)

musicdb=> 
musicdb=> 
musicdb=> create tablespace newtbs1 relative location 'tablespace/tablespace_2';
CREATE TABLESPACE
musicdb=> create tablespace ds_location1 relative location 'tablespace/tablespace_1';
CREATE TABLESPACE
musicdb=> \db
              List of tablespaces
     Name     | Owner |        Location         
--------------+-------+-------------------------
 ds_location1 | user1 | tablespace/tablespace_1
 music_tbs    | omm   | tablespace/test_ts1
 newtbs1      | user1 | tablespace/tablespace_2
 pg_default   | omm   | 
 pg_global    | omm   | 
(5 rows)

musicdb=> 

复制

2. 创建一个数据库newdb1，默认表空间为newtbs1

CREATE DATABASE newdb1 WITH TABLESPACE = newtbs1;
\l

musicdb=> CREATE DATABASE newdb1  WITH TABLESPACE = newtbs1;
CREATE DATABASE
musicdb=> \l
                         List of databases
   Name    | Owner | Encoding | Collate | Ctype | Access privileges 
-----------+-------+----------+---------+-------+-------------------
 musicdb   | omm   | UTF8     | C       | C     | 
 newdb1    | user1 | 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
(6 rows)
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3. 创建用户user5，并授予SYSADMIN权限，访问数据库newdb1，在表空间ds_location1上，创建一个表newt1（表结构自定义）

--执行下面的SQL语句，创建用户user5：
 CREATE USER user5 IDENTIFIED BY 'kunpeng@1234';
--授予user1数据库系统的SYSADMIN权限：
ALTER USER user5 SYSADMIN;
--使用user5用户，访问newdb1数据库
\c newdb1 user5
create table newt1 (id int primary key,col1 char(10)) tablespace ds_location1;

复制

musicdb=> CREATE USER user5 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
musicdb=> CREATE ROLE

musicdb=> ALTER USER user5 SYSADMIN;
ALTER ROLE
musicdb=> \du
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
 user1     | Sysadmin                                                                                                         | {}
 user5     | Sysadmin                                                                                                         | {}

                                                              List of roles
 Role name |                                                    Attributes                                                    | Member of 
-----------+------------------------------------------------------------------------------------------------------------------+-----------
 gaussdb   | Sysadmin                                                                                                         | {}
musicdb=> 
musicdb=> \c newdb1 user5
Password for user user5: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "newdb1" as user "user5".
newdb1=> create table newt1 (id int primary key,col1 char(10)) tablespace ds_location1;
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "newt1_pkey" for table "newt1"
CREATE TABLE
newdb1=> 
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4. 查看表所在的表空间

–建表newt1指定表空间ds_location1，查看表newt1所在的表空间：
select * from pg_tables where tablename = ‘newt1’;

newdb1=> select * from pg_tables where tablename = 'newt1';
 schemaname | tablename | tableowner |  tablespace  | hasindexes | hasrules | hastriggers | tablecreator |            created            |         last_ddl_time         
------------+-----------+------------+--------------+------------+----------+-------------+--------------+-------------------------------+-------------------------------
 public     | newt1     | user5      | ds_location1 | t          | f        | f           | user5        | 2022-12-01 11:47:28.821703+08 | 2022-12-01 11:47:28.821703+08
(1 row)

newdb1=> 
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5. 查看表空间newtbs1、 ds_location1上的对象

\c newdb1 user5
select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
from pg_class a, pg_tablespace tb  
where a.relkind in ('r', 'i')  
and a.reltablespace=tb.oid  
and tb.spcname='newtbs1'  
order by a.relpages desc;

select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
from pg_class a, pg_tablespace tb  
where a.relkind in ('r', 'i')  
and a.reltablespace=tb.oid  
and tb.spcname='ds_location1'  
order by a.relpages desc;

复制

newdb1=> \c newdb1 user5
Password for user user5: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "newdb1" as user "user5".
newdb1=> 
newdb1=> 
newdb1=> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
newdb1-> from pg_class a, pg_tablespace tb  
newdb1-> where a.relkind in ('r', 'i')  
newdb1-> and a.reltablespace=tb.oid  
newdb1-> and tb.spcname='newtbs1'  
newdb1-> order by a.relpages desc;
 relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------
(0 rows)

newdb1=> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
newdb1-> from pg_class a, pg_tablespace tb  
newdb1-> where a.relkind in ('r', 'i')  
newdb1-> and a.reltablespace=tb.oid  
newdb1-> newdb1-> and tb.spcname='ds_location1'  
order by a.relpages desc;
 relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------
 newt1   | r       |        0 | 0 bytes        |         16408 |    16410
(1 row)

newdb1=> 
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