openGauss每日一练第 8 天 | 一个数据库可以存储在多个表空间中

课后作业
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

1. 测试环境准备

--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;
revoke all on database omm from user1;
drop owned by user1 cascade;
drop user user1;
\c postgres
revoke all on database postgres from user1;
drop owned by user1 cascade;
drop user user1;

--检查表属主
select relname,relnamespace,relkind from pg_class 
  where relowner=(select oid from pg_roles where rolname='user1')
  order by 3 desc;
  
--检查用户的系统权限
SELECT * FROM pg_roles WHERE rolname='user1';

--检查用户的表权限
select * from information_schema.table_privileges where grantee='user1';

--检查用户的usage权限
select * from information_schema.usage_privileges where grantee='user1';

--检查用户在存储过程函数的执行权限
select * from information_schema.routine_privileges where grantee='user1';

--检查用户在表的列上的权限
select * from information_schema.column_privileges where grantee='user1';

--检查用户自定义类型上授予的USAGE权限	
select * from information_schema.udt_privileges where grantee='user1';

--执行下面的SQL语句，创建用户user5：
CREATE USER user5 IDENTIFIED BY 'kunpeng@1234';

--授予user5数据库系统的SYSADMIN权限：
ALTER USER user5 SYSADMIN;

2.创建实验数据库和表空间

CREATE TABLESPACE newtbs1 RELATIVE LOCATION 'tablespace/newtbs1_1';
CREATE TABLESPACE ds_location1 RELATIVE LOCATION 'tablespace/ds_location1_1';
CREATE DATABASE newdb1  WITH TABLESPACE = newtbs1;

--查看实例当前有哪些表空间：
\db

3. 使用 user5 用户，访问 newdb1 数据库 ，在表空间 ds_location1 上创建表newt1

\c newdb1 user5
create table newt1 (col1 char(10)) tablespace ds_location1;

-- 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');
-- 查看表newt1所在的表空间：
select * from pg_tables where tablename = 'newt1';

-- 创建表newt12未指定表空间，则在默认表空间（不显示默认表空间名）
create table newt12 (col1 char(10));
select * from pg_tables where tablename = 'newt12';

4. 查看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;

5. 查询对象

-- 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;

-- 查询表空间'ds_location1','newtbs1'上的对像
\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 in ('ds_location1','newtbs1') order by a.relpages desc;