How to Shrink Undo Segment In Oracle Database

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi
PL/SQL Release 10.2.0.4.0 - Production
CORE    10.2.0.4.0      Production
TNS for HPUX: Version 10.2.0.4.0 - Production
NLSRTL Version 10.2.0.4.0 - Production

1) sys > alter system set "_smu_debug_mode"=33554432; 
2) sys> alter system set "_undo_autotune"=false;   1) 2)合用才有效

select 'alter  rollback segment '|| substr(SEGMENT_NAME, 2, 10)|| ' shrink;'
 from dba_undo_extents where STATUS='EXPIRED'  and rownum <50 order by bytes desc;

alter system set "_undo_autotune"=true;  等undo回收後

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/13750068/viewspace-1155272/，如需轉載，請註明出處，否則將追究法律責任。