openGauss每日一练第8天 | openGauss中一个数据库可以存储在多个表空间中

1.创建表空间newtbs1、 ds_location1，查看表空间

omm=# create tablespace newtbs1 relative location 'tablespace/newtbs1';
CREATE TABLESPACEomm=# create tablespace ds_location1 relative location 'tablespace/ds_location1';
CREATE TABLESPACE
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 tablespace newtbs1 ;
CREATE DATABASE

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=# create user user5 sysadmin identified by 'abcd@123';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# \c newdb1 user5
Password for user user5: 
newdb1=> Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "newdb1" as user "user5".
newdb1=> create table newt1 (id integer) tablespace ds_location1 ;
CREATE TABLE

4.查看表所在的表空间

newdb1=> select * from pg_tables where tablename = 'newt1';
 schemaname | tablename | tableowner |  tablespace  | hasindexes | hasrules | hastriggers | tablecreator |            created            |         last_ddl_time     
    
------------+-----------+------------+--------------+------------+----------+-------------+--------------+-------------------------------+---------------------------
----
 public     | newt1     | user5      | ds_location1 | f          | f        | f           | user5        | 2022-12-01 11:26:30.560936+08 | 2022-12-01 11:26:30.560936
+08
(1 row)

5.查看表空间newtbs1、 ds_location1上的对象

newdb1=> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
newdb1-> from pg_class a, pg_tablespace tb  
newdb1-> where a.relkind in ('r', 'i')  
newdb1-> and a.reltablespace=tb.oid  
newdb1-> and tb.spcname='ds_location1'  
newdb1-> order by a.relpages desc;
 relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------
 newt1   | r       |        0 | 0 bytes        |         16403 |    16405
(1 row)
newdb1-> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  newdb1=> from pg_class a, pg_tablespace tb  
newdb1-> where a.relkind in ('r', 'i')  
newdb1-> and a.reltablespace=tb.oid  
newdb1-> and tb.spcname='newtbs1'  
newdb1-> order by a.relpages desc;
 relname | relkind | relpages | pg_size_pretty | reltablespace | relowner 
---------+---------+----------+----------------+---------------+----------
(0 rows)

newdb1=> select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),reltablespace,relowner  
newdb1-> from pg_class a  
newdb1-> where a.relkind in ('r', 'i')  
newdb1-> newdb1-> and reltablespace='0'  
newdb1-> order by a.relpages desc;