Oracle 12cR1 RAC
col sid for a10
col name for a20
col value for a20
select sid,name,value from v$spparameter where name='undo_tablespace';
SID NAME VALUE
---------- ------------------------------ --------------------
orcl2 undo_tablespace UNDOTBS2
orcl1 undo_tablespace UNDOTBS1
SYS@orcl1> show parameter create_file
NAME TYPE VALUE
------------------------------------ ---------------------- ------------------------------
db_create_file_dest string +DATADG
SYS@orcl1>
SYS@orcl1> show parameter undo
NAME TYPE VALUE
------------------------------------ ---------------------- ------------------------------
temp_undo_enabled boolean FALSE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS1
--不自动扩展，没有最大值
SYS@orcl1> alter tablespace undotbs1 add datafile size 10m;
SYS@orcl1> alter tablespace undotbs2 add datafile size 20m;
--扩容到30m
SYS@orcl1> alter database datafile '+DATADG/ORCL/DATAFILE/undotbs2.273.964970069' resize 30m;
--自动扩展，最大100M
SYS@orcl1> alter database datafile '+DATADG/ORCL/DATAFILE/undotbs2.273.964970069' autoextend on maxsize 100m;
col file_name for a50
set lines 200
select file_name,bytes/1024/1024 mb,maxbytes/1024/1024 max_mb from dba_data_files where tablespace_name like 'UNDOTBS%';
FILE_NAME MB MAX_MB
---------------------------------------------------------------------------- ------------- ----------
+DATADG/ORCL/DATAFILE/undotbs1.261.964970069 155 32767.9844
+DATADG/ORCL/DATAFILE/undotbs2.273.964970069 30 100
+DATADG/ORCL/DATAFILE/undotbs1.367.965681119 10 0
+DATADG/ORCL/DATAFILE/undotbs2.369.965681285 20 0
