发现数据库无法连接，报错内容截图如下：

0  用sql plus 命令登录数据库。

 sqlplus / as sysdba;

1 调整Oracle表空间大小(调整system01.dbf为4G)

alter database datafile '/home/db/oracle/oradata/orcl/system01.dbf' resize 4096m;

2 设置表空间自动增长

ALTER DATABASE DATAFILE '/home/db/oracle/oradata/orcl/system01.dbf'  AUTOEXTEND ON;//打开自动增长

3  查询表空间占用率及是否自增

select dbf.tablespace_name,
dbf.totalspace "总量(M)",
dbf.totalblocks as 总块数,
dfs.freespace "剩余总量(M)",
dfs.freeblocks "剩余块数",
(dfs.freespace / dbf.totalspace) * 100 "空闲比例"
from (select t.tablespace_name,
sum(t.bytes) / 1024 / 1024 totalspace,
sum(t.blocks) totalblocks
from dba_data_files t
group by t.tablespace_name) dbf,
(select tt.tablespace_name,
sum(tt.bytes) / 1024 / 1024 freespace,
sum(tt.blocks) freeblocks
from dba_free_space tt
group by tt.tablespace_name) dfs
where trim(dbf.tablespace_name) = trim(dfs.tablespace_name);

4  查看表空间是否开启了自动扩展的功能 

SELECT T.TABLESPACE_NAME,
D.FILE_NAME,
D.AUTOEXTENSIBLE,
D.BYTES,
D.MAXBYTES,
D.STATUS
FROM DBA_TABLESPACES T, DBA_DATA_FILES D
WHERE T.TABLESPACE_NAME = D.TABLESPACE_NAME
ORDER BY TABLESPACE_NAME, FILE_NAME;