Table space capacity query and expansion of Oracle Database

--  Querying table space usage （ Company ：M）
SELECT a.tablespace_name " Table space name ", 
total / (1024 * 1024) " Table space size (M)", 
free / (1024 * 1024) " Table space remaining size (M)", 
(total - free) / (1024 * 1024) " Table space usage size (M)", 
round((total - free) / total, 4) * 100 " Usage rate  %" 
FROM (SELECT tablespace_name, SUM(bytes) free 
FROM dba_free_space 
GROUP BY tablespace_name) a, 
(SELECT tablespace_name, SUM(bytes) total 
FROM dba_data_files 
GROUP BY tablespace_name) b 
WHERE a.tablespace_name = b.tablespace_name 

--  Extended table space 
-- Query table space and path 
select * from dba_data_files;

-- Method 1 ： Specify tablespace size 
alter database datafile '/u01/oracle/oradata/orcl/estamp.dbf' resize 1024m;
-- Method 2 ： New table space file 
alter tablespace estamp add datafile '/u01/oracle/oradata/orcl/estamp01.dbf' size 500m
-- Method 3 ： Turn on auto expansion 
-- Turn on auto grow off  To turn off automatic expansion 
ALTER DATABASE DATAFILE '/u01/oracle/oradata/orcl/grp.dbf' AUTOEXTEND ON;
-- Every time automatic growth 200m
ALTER DATABASE DATAFILE '/u01/oracle/oradata/orcl/estamp01.dbf' AUTOEXTEND ON NEXT 200M ;
-- Every time automatic growth 200m, The maximum table space is no more than 1G
ALTER DATABASE DATAFILE '/u01/oracle/oradata/orcl/grp.dbf' AUTOEXTEND ON NEXT 200M MAXSIZE 1024M;