openGauss 每日一练第8天

准备

• 切换用户，连接数据库

  su - omm
  gsql -r
  

1.创建表空间newtbs1、 ds_location1，查看表空间

-- 创建表空间 newtbs1 ds_location1
CREATE TABLESPACE newtbs1 RELATIVE LOCATION 'tablespace/newtbs1';
CREATE TABLESPACE ds_location1 RELATIVE LOCATION 'tablespace/ds_location1';

-- 查看当前有哪些表空间

omm=# \db
            List of tablespaces
   Name     | Owner |        Location         
--------------+-------+-------------------------
ds_location1 | omm   | tablespace/ds_location1
newtbs1      | omm   | tablespace/newtbs1
pg_default   | omm   | 
pg_global    | omm   | 
(4 rows)

2.创建一个数据库newdb1，默认表空间为newtbs1

omm=# CREATE DATABASE newdb1 WITH TABLESPACE =newtbs1 ;
CREATE DATABASE
omm=# \l+
                                                          List of databases
   Name    | Owner | Encoding | Collate | Ctype | Access privileges | Size  | Tablespace |                Description                 
-----------+-------+----------+---------+-------+-------------------+-------+------------+--------------------------------------------
 newdb1    | omm   | UTF8     | C       | C     |                   | 12 MB | newtbs1    | 
 omm       | omm   | UTF8     | C       | C     |                   | 12 MB | pg_default | 
 postgres  | omm   | UTF8     | C       | C     |                   | 12 MB | pg_default | default administrative connection database
 template0 | omm   | UTF8     | C       | C     | =c/omm           +| 12 MB | pg_default | default template for new databases
           |       |          |         |       | omm=CTc/omm       |       |            | 
 template1 | omm   | UTF8     | C       | C     | =c/omm           +| 12 MB | pg_default | unmodifiable empty database
           |       |          |         |       | omm=CTc/omm       |       |            | 
(5 rows)

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）

omm=# drop user user5 ;
DROP ROLE
omm=# CREATE USER user5 IDENTIFIED BY 'abcd@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# alter user user5 sysadmin ;
ALTER ROLE
omm=# \du
                                                              List of roles
 Role name |                                                    Attributes                                                    | Member of 
-----------+------------------------------------------------------------------------------------------------------------------+-----------
 gaussdb   | Sysadmin                                                                                                         | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
 user5     | Sysadmin                                                                                                         | {}

-- 使用user5 连接到newdb1 库
omm=# \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".

-- 在表空间ds_location1上创建 表newt1
newdb1=> create table newt1(textcol char(30)) tablespace ds_location1 ;
CREATE TABLE
newdb1=> \dt+
                                     List of relations
 Schema | Name  | Type  | Owner |  Size   |             Storage              | Description 
--------+-------+-------+-------+---------+----------------------------------+-------------
 public | newt1 | table | user5 | 0 bytes | {orientation=row,compression=no} | 
(1 row)

4.查看表所在的表空间

newdb1=> select * from pg_tables where tablename = 'newt1';
                                                                                 musicdb
 schemaname | tablename | tableowner |  tablespace  | hasindexes | hasrules | hastriggers | tablecreator |            created            |         last_ddl_time         
------------+-----------+------------+--------------+------------+----------+-------------+--------------+-------------------------------+-------------------------------
 public     | newt1     | user5      | ds_location1 | f          | f        | f           | user5        | 2022-12-02 09:35:33.950938+08 | 2022-12-02 09:35:33.950938+08
(1 row)

5.查看表空间newtbs1、 ds_location1上的对象

-- 查看ds_location1 上的对象
newdb1=> 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
 relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------
 newt1   | r       |        0 | 0 bytes        |         16392 |    16398
(1 row)


-- 查看 newtbs1 上的对象
newdb1=> 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;

                                 musicdb
 relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------
(0 rows)