ORA-1555 error with AUM already enabled

  • From: Janine Sisk <janine@xxxxxxxxxx>
  • To: oracle-l L <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 25 May 2010 15:22:24 -0700

A full export of my database takes far longer on AWS than it does on my old 
Linux server (30 minutes vs 2+ hours).  During the export, I receive the 
following error:

EXP-00056: ORACLE error 1555 encountered
ORA-01555: snapshot too old: rollback segment number 1 with name 
"_SYSSMU1_3780397527$" too small

I checked the parameters that control automatic undo management and found them 
to be set correctly:

SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1


I tried running the export again, to see whether Oracle would have 
automatically adjusted something to fix the problem, but it failed again.

Is this just one of those freak cases where circumstances have psyched out the 
automatic feature, or is there something I can do to fix it, beyond whatever 
the manager is doing?  Clearly the immediate problem is that my rollback 
segments are too small, but since Oracle is managing them I hesitate to go make 
them bigger myself.  The longer range issue is the slow performance of the 
virtual disk drives, which is something I haven't delved into yet.

thanks,

janine

--
//www.freelists.org/webpage/oracle-l


Other related posts: