oracle multi-tenant (local and shared undo tablespace)

Switch to share undo mode

This is a local undo tablespace
select property_name, property_value
from database_properties
where property_name ='LOCAL_UNDO_ENABLED';

there is a undo
tablespace select con_id, tablespace_name
from cdb_tablespaces
where contents ='UNDO';

view data files
alter session set container = pdb2;
select file_name
from dba_data_files
where tablespace_name ='UNDOTBS1';


shutdown immediate;
startup upgrade;
alter database local undo off;
shutdown immediate;
startup;

view the modified results, the


original data file and table space are still in
alter session set container = pdb2;
select file_name
from dba_data_files
where tablespace_name = 'UNDOTBS1';


Delete the table space
drop tablespace undotbs1;

Switch to local undo mode

现在是共享撤消模式


shutdown immediate;
startup upgrade;
alter database local undo on;
shutdown immediate;
startup;

select property_name, property_value
from database_properties
where property_name = ‘LOCAL_UNDO_ENABLED’;


自动生成了PDB2的UNDO表空间
alter session set container = cdb$root;
select con_id, tablespace_name
from cdb_tablespaces
where tablespace_name LIKE ‘UNDO%’
order by con_id;