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10天 | openGauss逻辑结构：表空间管理
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。
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.创建表空间、多个数据库和用户
#第一次进入等待15秒
#数据库启动中…
1）–连接数据库
su - omm
gsql -r
root@modb:~#
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.执行如下命令创建用户jack
CREATE USER jack IDENTIFIED BY ‘kunpeng@1234’;
omm=# CREATE USER jack IDENTIFIED BY 'kunpeng@1234';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=#
3.创建表空间、表
1）–执行下面的SQL语句，创建表空间t_tbspace：
CREATE TABLESPACE t_tbspace RELATIVE LOCATION ‘tablespace/t_tbspace1’;
omm=# CREATE TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
omm=# CREATE TABLESPACE
omm=#
2）–查看系统有哪些表空间
select oid,* from pg_tablespace ;
或
\db
omm=# select oid,* from pg_tablespace ;
omm=# oid | spcname | spcowner | spcacl | spcoptions | spcmaxsize | relative
-------+------------+----------+--------+------------+------------+----------
1663 | pg_default | 10 | | | | f
1664 | pg_global | 10 | | | | f
16393 | t_tbspace | 10 | | | | t
(3 rows)
omm=# \db
t_tbspace | omm | tablespace/t_tbspace1
(3 rows)
omm=# List of tablespaces
Name | Owner | Location
------------+-------+-----------------------
pg_default | omm |
pg_global | omm |
omm=#
3）–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;
omm=# GRANT CREATE ON TABLESPACE t_tbspace TO jack;
omm=# GRANT
omm=#
4）–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
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;
\q
omm=>
omm=> CREATE TABLE foo(i int) TABLESPACE t_tbspace;
CREATE TABLE
omm=> \q
omm@modb:~$
4.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=#
5.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,relowner
from pg_class a
where 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(# omm(# from pg_class a
where a.relkind in ('r', 'i') and reltablespace='0'
omm(# omm-# )
omm-# select *
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 | reltablespace | relowner
------------------------------------------+---------+----------+----------------+---------------+----------
streaming_gather_agg_index | i | 2 | 16 kB | 0 | 10
snapshot_id_key | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_lookupidxid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_schema_change_index | i | 1 | 8192 bytes | 0 | 10
streaming_reaper_status_id_index | i | 1 | 8192 bytes | 0 | 10
streaming_reaper_status_oid_index | i | 1 | 8192 bytes | 0 | 10
snapshot_pkey | i | 1 | 8192 bytes | 0 | 10
statement_history_time_idx | i | 1 | 8192 bytes | 0 | 10
streaming_stream_oid_index | i | 1 | 8192 bytes | 0 | 10
streaming_stream_relid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_relid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_defrelid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_oid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_matrelid_index | i | 1 | 8192 bytes | 0 | 10
plan_table_data | r | 0 | 0 bytes | 0 | 10
statement_history | r | 0 | 0 bytes | 0 | 10
streaming_stream | r | 0 | 0 bytes | 0 | 10
snapshot | r | 0 | 0 bytes | 0 | 10
streaming_reaper_status | r | 0 | 0 bytes | 0 | 10
streaming_cont_query | r | 0 | 0 bytes | 0 | 10
--More-- streaming_cont_query_id_index | i | 1 | 8192 bytes | 0 | 10
(21 rows)
omm=#
6.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,relowner
from pg_class a, pg_tablespace tb
where a.relkind in (‘r’, ‘i’)
and a.reltablespace=tb.oid
and 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-# from pg_class a, pg_tablespace tb
omm-# where 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 | 16393 | 16389
(1 row)
omm=#
7.重命名表空间
1）–命名表空间t_tbspace为app_tbs
ALTER TABLESPACE t_tbspace RENAME TO app_tbs;
omm=#
omm=# ALTER TABLESPACE t_tbspace RENAME TO app_tbs;
ALTER TABLESPACE
omm=#
2）–执行下面的gsql命令，查看数据库当前的表空间信息：
\db
omm=# \db
List of tablespaces
Name | Owner | Location
------------+-------+-----------------------
app_tbs | omm | tablespace/t_tbspace1
pg_default | omm |
pg_global | omm |
(3 rows)
omm=#
8.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;
omm=# drop table jack.foo ;
DROP TABLE
omm=# DROP TABLESPACE app_tbs;
DROP TABLESPACE
omm=#
课程总结
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
2、查看表空间t_tbspace的oid和大小
3、查看数据库在默认表空间下有哪些对象
4、查看数据库在非默认表空间下有哪些对象
5、重命名表空间
6、删除表空间
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
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 ‘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 | | | | f
1664 | pg_global | 10 | | | | f
16401 | t_tbspace | 10 | | | | t
(3 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(i int) tablespace t_tbspace;
CREATE TABLE
omm=> \q
2、查看表空间t_tbspace的oid和大小
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
--------------------
4096
(1 row)
omm=# select oid,* from pg_tablespace ;
oid | spcname | spcowner | spcacl | spcoptions | spcmaxsize | relative
-------+------------+----------+------------------------+------------+------------+----------
1663 | pg_default | 10 | | | | f
1664 | pg_global | 10 | | | | f
16412 | app_ts | 10 | | | | t
16421 | t_tbspace | 10 | {omm=C/omm,test=C/omm} | | | t
(6 rows)
omm=# 16389 | enmtbs | 10 | | | | t
16410 | enmtbs2 | 10 | | | | t
omm=#
3、查看数据库在默认表空间下有哪些对象
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(# )
select *
omm-# 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 | reltablespace | relowner
------------------------------------------+---------+----------+----------------+---------------+----------
streaming_gather_agg_index | i | 2 | 16 kB | 0 | 10
snapshot_id_key | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_lookupidxid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_schema_change_index | i | 1 | 8192 bytes | 0 | 10
streaming_reaper_status_id_index | i | 1 | 8192 bytes | 0 | 10
streaming_reaper_status_oid_index | i | 1 | 8192 bytes | 0 | 10
snapshot_pkey | i | 1 | 8192 bytes | 0 | 10
statement_history_time_idx | i | 1 | 8192 bytes | 0 | 10
streaming_stream_oid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_defrelid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_id_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_oid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_matrelid_index | i | 1 | 8192 bytes | 0 | 10
streaming_stream_relid_index | i | 1 | 8192 bytes | 0 | 10
streaming_cont_query_relid_index | i | 1 | 8192 bytes | 0 | 10
plan_table_data | r | 0 | 0 bytes | 0 | 10
statement_history | r | 0 | 0 bytes | 0 | 10
streaming_stream | r | 0 | 0 bytes | 0 | 10
snapshot | r | 0 | 0 bytes | 0 | 10
streaming_reaper_status | r | 0 | 0 bytes | 0 | 10
streaming_cont_query | r | 0 | 0 bytes | 0 | 10
(21 rows)
4、查看数据库在非默认表空间下有哪些对象
omm-# reltablespace,relowner
omm-# from pg_class a, pg_tablespace tb
omm-# where 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
---------+---------+----------+----------------+---------------+----------
t1 | r | 0 | 0 bytes | 16401 | 16397
(1 row)
5、重命名表空间
ALTER TABLESPACE
omm=# \db
List of tablespaces
Name | Owner | Location
------------+-------+-----------------------
pg_default | omm |
pg_global | omm |
xx1 | omm | tablespace/t_tbspace1
(3 rows)
6、删除表空间
DROP TABLE
omm=# drop tablespace xx1 ;
DROP TABLESPACE
omm=# \db
List of tablespaces
Name | Owner | Location
------------+-------+----------
pg_default | omm |
pg_global | omm |
(2 rows)
