一、学习目标

表空间是数据的容器。掌握表空间的管理，包括创建表空间、删除表空间、重命名表空间、查看表空间的情况。

二、课程学习

通过使用表空间，管理员可以控制一个数据库安装的磁盘布局。

表空间对应于一个文件系统目录，假定数据库节点数据目录/pg_location/mount1/path1是用户拥有读写权限的空目录。
openGauss自带了两个表空间：pg_default和pg_global。

• 默认表空间pg_default：用来存储非共享系统表、用户表、用户表index、临时表、临时表index、内部临时表的默认表空间。对应存储目录为实例数据目录下的base目录。
• 共享表空间pg_global：用来存放共享系统表的表空间。对应存储目录为实例数据目录下的global目录。

1.执行如下命令创建用户jack
CREATE USER jack IDENTIFIED BY ‘kunpeng@1234’;
2.创建表空间、表

--执行下面的SQL语句，创建表空间t_tbspace：
CREATE TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
--查看系统有哪些表空间
select oid,* from pg_tablespace ;
或
\db
--数据库系统管理员执行如下命令将“t_tbspace”表空间的访问权限赋予数据用户jack。
GRANT CREATE ON TABLESPACE t_tbspace TO jack;
--执行如下命令，使用jack用户在指定表空间t_tbspace创建表。
\c omm jack
CREATE TABLE foo(i int) TABLESPACE t_tbspace;
\q

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=# CREATE USER jack IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# CREATE TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
CREATE TABLESPACE
omm=# select oid,* from pg_tablespace;oid  |  spcname   | spcowner | spcacl | spcoptions | spcmaxsize | relative 
-------+------------+----------+--------+------------+------------+----------1663 | pg_default |       10 |        |            |            | f1664 | pg_global  |       10 |        |            |            | f16389 | music_tbs  |       10 |        |            |            | t16398 | newtbs1    |       10 |        |            |            | t16406 | t_tbspace  |       10 |        |            |            | t
omm=# (5 rows)
omm=# \dbList of tablespacesName    | Owner |       Location        
------------+-------+-----------------------music_tbs  | omm   | tablespace/test_ts1newtbs1    | omm   | tablespace/test_ts2pg_default | omm   | pg_global  | omm   | t_tbspace  | omm   | tablespace/t_tbspace1
(5 rows)                                 ^
omm=# GRANT CREATE ON TABLESPACE t_tbspace TO jack;
GRANT
omm=# \c omm jack
Password for user jack: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "omm" as user "jack".
omm=> CREATE TABLE foo(i int) TABLESPACE t_tbspace;
CREATE TABLE
omm=> \q
omm@modb:~$ 

3.查看表空间t_tbspace的大小
gsql -r
SELECT PG_TABLESPACE_SIZE(‘t_tbspace’);

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 PG_TABLESPACE_SIZE('t_tbspace');pg_tablespace_size 
--------------------8192
(1 row)omm=# 

4.查看数据库在默认表空间下有哪些对象

with objectInDefaultTS as( select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relownerfrom pg_class awhere a.relkind in ('r', 'i')  and reltablespace='0')select * from objectInDefaultTS where relname not like 'pg_%' and relname not like 'gs_%' and relname not like 'sql_%'order by relpages desc;

omm=# with objectInDefaultTS as
omm-#           ( select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),
omm(#                   reltablespace,relowner
omm(#             from pg_class a
omm(#             where a.relkind in ('r', 'i')  and reltablespace='0'
omm(# omm-#          )select * 
omm-#  from objectInDefaultTS 
omm-# omm-#    where relname not like 'pg_%' and relname not like 'gs_%' and relnameike 'sql_%'order by relpages desc;relname                  | relkind | relpages | pg_size_pretty | re
ltablespace | relowner 
------------------------------------------+---------+----------+----------------+---
------------+----------streaming_gather_agg_index               | i       |        2 | 16 kB          |   0 |       10snapshot_id_key                          | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_lookupidxid_index   | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_schema_change_index | i       |        1 | 8192 bytes     |   0 |       10streaming_reaper_status_id_index         | i       |        1 | 8192 bytes     |   0 |       10streaming_reaper_status_oid_index        | i       |        1 | 8192 bytes     |   0 |       10snapshot_pkey                            | i       |        1 | 8192 bytes     |   0 |       10statement_history_time_idx               | i       |        1 | 8192 bytes     |   0 |       10streaming_stream_oid_index               | i       |        1 | 8192 bytes     |   0 |       10streaming_stream_relid_index             | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_relid_index         | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_defrelid_index      | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_id_index            | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_oid_index           | i       |        1 | 8192 bytes     |   0 |       10streaming_cont_query_matrelid_index      | i       |        1 | 8192 bytes     |   0 |       10plan_table_data                          | r       |        0 | 0 bytes        |   0 |       10statement_history                        | r       |        0 | 0 bytes        |   0 |       10streaming_stream                         | r       |        0 | 0 bytes        |   0 |       10snapshot                                 | r       |        0 | 0 bytes        |   0 |       10streaming_reaper_status                  | r       |        0 | 0 bytes        |   0 |       10streaming_cont_query                     | r       |        0 | 0 bytes        |   0 |       10
(21 rows)omm=# 

5.查看数据库在非默认表空间下有哪些对象

--执行下面的SQL语句，查询数据库studentdb的非默认表空间t_tbspace下有哪些对象：select relname,relkind,relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relownerfrom pg_class a, pg_tablespace tbwhere a.relkind in ('r', 'i')and a.reltablespace=tb.oidand tb.spcname='t_tbspace'order by a.relpages desc;

omm=#  select relname,relkind,relpages,pg_size_pretty(pg_relation_size(a.oid)),
omm-#           reltablespace,relowner
omm-# omm-#    from pg_class a, pg_tablespace tbwhere a.relkind in ('r', 'i')
omm-#    and a.reltablespace=tb.oid
omm-#    and tb.spcname='t_tbspace'
omm-#    order by a.relpages desc;relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------foo     | r       |        0 | 0 bytes        |         16406 |    16402
(1 row)omm=# 

6.重命名表空间
–命名表空间t_tbspace为app_tbs
ALTER TABLESPACE t_tbspace RENAME TO app_tbs;
–执行下面的gsql命令，查看数据库当前的表空间信息：
\db

omm=# ALTER TABLESPACE t_tbspace RENAME TO app_tbs;
ALTER TABLESPACE
omm=# \dbList of tablespacesName    | Owner |       Location        
------------+-------+-----------------------app_tbs    | omm   | tablespace/t_tbspace1music_tbs  | omm   | tablespace/test_ts1newtbs1    | omm   | tablespace/test_ts2pg_default | omm   | pg_global  | omm   | 
(5 rows)omm=# 

7.删除表空间

--用户必须是表空间的owner或者系统管理员才能删除表空间。需要先删除表空间的对象，再删除表空间app_ts：
drop table jack.foo ;
DROP TABLESPACE app_tbs;
\db

omm=# drop table jack.foo ;
DROP TABLE
omm=# DROP TABLESPACE app_tbs;
DROP TABLESPACE
omm=# \dbList of tablespacesName    | Owner |      Location       
------------+-------+---------------------music_tbs  | omm   | tablespace/test_ts1newtbs1    | omm   | tablespace/test_ts2pg_default | omm   | pg_global  | omm   | 
(4 rows)omm=# 

三、课后作业

1、创建表空间t_tbspace、用户test，并使用test，在这个表空间上创建表t1

--创建用户test
CREATE USER test IDENTIFIED BY 'hello@1234';
\du
--创建表空间t_tbspace
CREATE TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
\db
--数据库系统管理员执行如下命令将“t_tbspace”表空间的访问权限赋予数据用户test。
GRANT CREATE ON TABLESPACE t_tbspace TO test;
\c omm test
CREATE TABLE t1(id int primary key,c1 char(9)) TABLESPACE t_tbspace;
\q

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=# CREATE USER test IDENTIFIED BY 'hello@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# \duList of rolesRole name |                                                    Attributes           | Member of 
-----------+-------------------------------------------------------------------------
-----------------------------------------+-----------gaussdb   | Sysadmin                                                                | {}jack      |                                                                         | {}| {}user1     | Sysadmin                                                                omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitor
admin, Operatoradmin, Policyadmin, UseFT | {}test      |                                                                         | {}omm=# CREATE TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
CREATE TABLESPACE
omm=# \dbmusic_tbs  | omm   | tablespace/test_ts1newtbs1    | omm   | tablespace/test_ts2pg_default | omm   |             List of tablespacesName    | Owner |       Location        
------------+-------+-----------------------
omm=# pg_global  | omm   | t_tbspace  | omm   | tablespace/t_tbspace1
(5 rows)omm=# GRANT CREATE ON TABLESPACE t_tbspace TO test;
GRANT
omm=# \c omm test
Password for user test: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "omm" as user "test".
omm=> CREATE TABLE t1(id int primary key,c1 char(9)) TABLESPACE t_tbspace;
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "t1_pkey" for table "t1"
CREATE TABLE
omm=> 

2、查看表空间t_tbspace的oid和大小

select oid,* from pg_tablespace;
SELECT PG_TABLESPACE_SIZE(‘t_tbspace’);

omm=> select oid,* from pg_tablespace;oid  |  spcname   | spcowner |         spcacl         | spcoptions | spcmaxsize | r
elative 
-------+------------+----------+------------------------+------------+------------+--
--------1663 | pg_default |       10 |                        |            |            | f1664 | pg_global  |       10 |                        |            |            | f16389 | music_tbs  |       10 |                        |            |            | t16398 | newtbs1    |       10 |                        |            |            | t16424 | t_tbspace  |       10 | {omm=C/omm,test=C/omm} |            |            | t
(5 rows)omm=> SELECT PG_TABLESPACE_SIZE('t_tbspace');pg_tablespace_size 
--------------------8192
(1 row)omm=> 

3、查看数据库在默认表空间下有哪些对象

with objectInDefaultTS as( select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relownerfrom pg_class awhere a.relkind in ('r', 'i')  and reltablespace='0')select * from objectInDefaultTS where relname not like 'pg_%' and relname not like 'gs_%' and relname not like 'sql_%'order by relpages desc;

omm=# with objectInDefaultTS as
omm-#           ( select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),
omm(#                   reltablespace,relowner
omm(#             from pg_class a
omm(#             where a.relkind in ('r', 'i')  and reltablespace='0'
omm(# omm-#  select * )
omm-#  from objectInDefaultTS 
omm-#    where relname not like 'pg_%' and relname not like 'gs_%' and relname not like 'sql_%'
omm-#  order by relpages desc;relname                  | relkind | relpages | pg_size_pretty | rel
tablespace | relowner 
------------------------------------------+---------+----------+----------------+----
-----------+---------- streaming_reaper_status_id_index         | i       |        1 | 8192 bytes     |    0 |       10streaming_reaper_status_oid_index        | i       |        1 | 8192 bytes     |    streaming_gather_agg_index               | i       |        2 | 16 kB          |    0 |       10statement_history_time_idx               | i       |        1 | 8192 bytes     |    0 |       10snapshot_id_key                          | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_lookupidxid_index   | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_schema_change_index | i       |        1 | 8192 bytes     |    0 |       100 |       10snapshot_pkey                            | i       |        1 | 8192 bytes     |    streaming_stream_oid_index               | i       |        1 | 8192 bytes     |    
--More--         0 |       10t1_pkey                                  | i       |        1 | 8192 bytes     |    0 |    164200 |       10streaming_stream_relid_index             | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_relid_index         | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_defrelid_index      | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_id_index            | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_oid_index           | i       |        1 | 8192 bytes     |    0 |       10streaming_cont_query_matrelid_index      | i       |        1 | 8192 bytes     |    0 |       10plan_table_data                          | r       |        0 | 0 bytes        |    0 |       10statement_history                        | r       |        0 | 0 bytes        |    0 |       10streaming_stream                         | r       |        0 | 0 bytes        |    0 |       10snapshot                                 | r       |        0 | 0 bytes        |    0 |       10streaming_reaper_status                  | r       |        0 | 0 bytes        |    0 |       10streaming_cont_query                     | r       |        0 | 0 bytes        |    0 |       10
(22 rows)

4、查看数据库在非默认表空间下有哪些对象

--执行下面的SQL语句，查询数据库studentdb的非默认表空间t_tbspace下有哪些对象：select relname,relkind,relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relownerfrom pg_class a, pg_tablespace tbwhere a.relkind in ('r', 'i')and a.reltablespace=tb.oidand tb.spcname='t_tbspace'order by a.relpages desc;

omm=# omm-#  select relname,relkind,relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner
omm-# omm-#    from pg_class a, pg_tablespace tb
omm-#    where a.relkind in ('r', 'i')and a.reltablespace=tb.oid
omm-#    and tb.spcname='t_tbspace'
omm-#    order by a.relpages desc;relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------t1      | r       |        0 | 0 bytes        |         16424 |    16420
(1 row)omm=# 

5、重命名表空间

–命名表空间t_tbspace为new_tbspace
ALTER TABLESPACE t_tbspace RENAME TO new_tbspace;
–执行下面的gsql命令，查看数据库当前的表空间信息：
\db

omm=# ALTER TABLESPACE t_tbspace RENAME TO new_tbspace;
ALTER TABLESPACE
omm=# \dbList of tablespacesName     | Owner |       Location        
-------------+-------+-----------------------music_tbs   | omm   | tablespace/test_ts1new_tbspace | omm   | tablespace/t_tbspace1newtbs1     | omm   | tablespace/test_ts2pg_default  | omm   | pg_global   | omm   | 
(5 rows)omm=# 

6、删除表空间

omm=# drop table test.t1;
DROP TABLE
omm=# drop tablespace new_tbspace;
DROP TABLESPACE
omm=# \dbList of tablespacesName    | Owner |      Location       
------------+-------+---------------------music_tbs  | omm   | tablespace/test_ts1newtbs1    | omm   | tablespace/test_ts2pg_default | omm   | pg_global  | omm   | 
(4 rows)omm=#