作者：马顺华
从事运维管理工作多年，目前就职于某科技有限公司，熟悉运维自动化、OceanBase部署运维、MySQL 运维以及各种云平台技术和产品。并已获得OceanBase认证OBCA、OBCP证书。
第 8 天 | openGauss中一个数据库可以存储在多个表空间中
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.
课程学习
openGauss中一个数据库可以存储在多个表空间中
1.连接数据库，准备测试环境
#第一次进入等待15秒
#数据库启动中…
1）–连接数据库,进入数据库omm
su - omm
gsql -r
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=#
2）–进入数据库omm，创建表空间、测试数据库
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;
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;
omm=# 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=#
3）–执行下面的SQL语句，创建用户user1：
CREATE USER user1 IDENTIFIED BY ‘kunpeng@1234’;
omm=# CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=#
4）–授予user1数据库系统的SYSADMIN权限：
ALTER USER user1 SYSADMIN;
omm=# ALTER USER user1 SYSADMIN;
ALTER ROLE
omm=#
2.创建表空间、查看表空间
1）–执行下面的命令，查看当前表空间：
\db
omm=# \db
List of tablespaces
Name | Owner | Location
------------+-------+---------------------
music_tbs | omm | tablespace/test_ts1
pg_default | omm |
pg_global | omm |
(3 rows)
omm=#
2）–创建一个新的名为ds_location1的表空间：
CREATE TABLESPACE ds_location1 RELATIVE LOCATION ‘tablespace/tablespace_1’;
omm=# CREATE TABLESPACE ds_location1 RELATIVE LOCATION 'tablespace/tablespace_1';
CREATE TABLESPACE
omm=#
omm=#
3）–执行下面的命令，查看实例当前有哪些表空间：
\db
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=#
3.使用user1用户，访问musicdb数据库 ，在表空间ds_location1上创建表warehouse_t1:
\c musicdb user1
omm=# \c musicdb user1
Password for user user1:
musicdb=> 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;
4.查看musicdb数据库目前有哪些表：
select table_catalog, table_schema, table_name, table_type
from information_schema.tables
where table_schema not in (‘pg_catalog’, ‘information_schema’,‘dbe_perf’);
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');
musicdb | dbe_pldeveloper | gs_errors | BASE TABLE
musicdb | dbe_pldeveloper | gs_source | BASE TABLE
(3 rows)
musicdb=> table_catalog | table_schema | table_name | table_type
---------------+-----------------+------------+------------
musicdb | db4ai | snapshot | BASE TABLE
musicdb=>
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）
1）–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’;
musicdb=> select * from pg_tables where tablename = 'warehouse_t1';
schemaname | tablename | tableowner | tablespace | hasindexes | hasrules | hastriggers | tablecreator | created | last_ddl_time
------------+-----------+------------+------------+------------+----------+-------------+--------------+---------+---------------
(0 rows)
musicdb=>
2）–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’;
musicdb=> create table warehouse_t12 (col1 char(10));
musicdb=> CREATE TABLE
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 10:25:24.413938+08 | 2022-
12-01 10:25:24.413938+08
(1 row)
musicdb=>
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;
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=>
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;
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')
musicdb-> musicdb-> and reltablespace='0'
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_depend_reference_index | i | 34 | 272 kB | 0 | 10
pg_description | r | 31 | 248 kB | 0 | 10
pg_attribute_relid_attnum_index | i | 30 | 240 kB | 0 | 10
pg_type | r | 20 | 160 kB | 0 | 10
pg_depend_depender_index | i | 34 | 272 kB | 0 | 10
pg_statistic | r | 19 | 152 kB | 0 | 10
pg_description_o_c_o_index | i | 16 | 128 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
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 | 10
pg_statistic_relid_kind_att_inh_index | i | 4 | 32 kB | 0 | 10
pg_ts_config_map_index | i | 4 | 32 kB | 0 | 10
pg_amproc_oid_index | i | 4 | 32 kB | 0 | 10
pg_toast_2618_index | i | 4 | 32 kB | 0 | 10
pg_rewrite_rel_rulename_index | i | 4 | 32 kB | 0 | 10
pg_amproc_fam_proc_index | i | 4 | 32 kB | 0 | 10
pg_amproc | r | 4 | 32 kB | 0 | 10
pg_opclass | r | 4 | 32 kB | 0 | 10
pg_cast_oid_index | i | 4 | 32 kB | 0 | 10
pg_cast_source_target_index | i | 4 | 32 kB | 0 | 10
pg_conversion | r | 3 | 24 kB | 0 | 10
pg_cast | r | 3 | 24 kB | 0 | 10
pg_opfamily | r | 3 | 24 kB | 0 | 10
pg_conversion_default_index | i | 2 | 16 kB | 0 | 10
pg_conversion_name_nsp_index | i | 2 | 16 kB | 0 | 10
pg_conversion_oid_index | i | 2 | 16 kB | 0 | 10
--More--
8.查询表空间ds_location1上的对像
\c musicdb user1
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=>
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;
musicdb=> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner
musicdb-> from pg_class a, pg_tablespace tb
musicdb-> 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
---------+---------+----------+----------------+---------------+----------
(0 rows)
musicdb=>
课程总结
1.创建表空间newtbs1、 ds_location1，查看表空间
2.创建一个数据库newdb1，默认表空间为newtbs1
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）
4.查看表所在的表空间
5.查看表空间newtbs1、 ds_location1上的对象
