管理undo tablespace
管理undo tablespace0.创建undo tablespace :CREATE UNDO TABLESPACE undotbs_02DATAFILE '/u01/oracle/rbdb1/undo0201.dbf' SIZE 2M REUSE AUTOEXTEND ON;1.添加一个数据文件:ALTER TABLESPACE undotbs_01ADD DATAFILE '/u01/oracle/rbdb1/undo0102.dbf' AUTOEXTEND ON NEXT 1MMAXSIZE UNLIMITED;2.删除undo tablespace:DROP TABLESPACE undotbs_01;3.却换undo tablespace:ALTER SYSTEM SET UNDO_TABLESPACE = undotbs_02;ALTER SYSTEM SET UNDO_TABLESPACE = '';-------------系统会自动切换到下一个可用的undo tablespace