openGauss每日一练第10天|表空间管理

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。

--创建表空间t_tbspace、用户test：
CREATE TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
CREATE USER test IDENTIFIED BY 'Mygstest@1234';
--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;
--执行如下命令，使用test用户在指定表空间t_tbspace创建表t1。
\c omm test
create table t1(product_id INTEGER,product_name Char(20),category Char(30));
insert into t1 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
select * from t1;
\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 TABLESPACE t_tbspace RELATIVE LOCATION 'tablespace/t_tbspace1';
CREATE TABLESPACE
omm=# CREATE USER test IDENTIFIED BY 'Mygstest@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
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(product_id INTEGER,product_name Char(20),category Char(30));
CREATE TABLE
omm=> insert into t1 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
INSERT 0 4
omm=> select * from t1;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamaze               | toys                          
       1700 | wait interface       | Books                         
       1666 | harry potter         | toys                          
(4 rows)

omm=> 

2、查看表空间t_tbspace的oid和大小。

gsql -r
SELECT PG_TABLESPACE_SIZE('t_tbspace');
select oid,* from pg_tablespace;

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
 16389 | t_tbspace  |       10 | {omm=C/omm,test=C/omm} |            |            | t
(3 rows)

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,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-> omm(>           ( select relname, relkind, relpages,pg_size_pretty(pg_relation_size(a.oid)),
                  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 | reltablespace | relowner 
------------------------------------------+---------+----------+----------------+---------------+----------
 streaming_gather_agg_index               | i       |        2 | 16 kB          |             0 |       10
 statement_history_time_idx               | i       |        1 | 8192 bytes     |             0 |       10
 snapshot_id_key                          | 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_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
 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_id_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
 streaming_reaper_status                  | r       |        0 | 0 bytes        |             0 |       10
 snapshot                                 | r       |        0 | 0 bytes        |             0 |       10
 streaming_cont_query                     | r       |        0 | 0 bytes        |             0 |       10
 t1                                       | r       |        0 | 8192 bytes     |             0 |    16390
(22 rows)

4、查看数据库在非默认表空间下有哪些对象。

 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 
---------+---------+----------+----------------+---------------+----------
(0 rows)

omm=> 

5、重命名表空间。

--命名表空间t_tbspace为test_tbs
ALTER TABLESPACE t_tbspace RENAME TO test_tbs;
\db

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=# \db
            List of tablespaces
    Name    | Owner |       Location        
------------+-------+-----------------------
 pg_default | omm   | 
 pg_global  | omm   | 
 t_tbspace  | omm   | tablespace/t_tbspace1
(3 rows)

omm=# ALTER TABLESPACE t_tbspace RENAME TO test_tbs;
omm=# ALTER TABLESPACE

omm=# \db
            List of tablespaces
    Name    | Owner |       Location        
------------+-------+-----------------------
 pg_default | omm   | 
 pg_global  | omm   | 
 test_tbs   | omm   | tablespace/t_tbspace1
(3 rows)

omm=# 

6、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test_ts：
drop table test.t1;
DROP TABLESPACE test_tbs;

omm=# drop table test.t1;
DROP TABLE
omm=# DROP TABLESPACE test_tbs;
DROP TABLESPACE
omm=#