Oracle Database Discussions

Need some info...

Currently seeing ORA-01555: snapshot too old: rollback segment number 18 with name "_SYSSMU18$" too small.

Info:

SQL> show parameter undo

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
undo_management string AUTO
undo_retention integer 4200
undo_suppress_errors boolean FALSE
undo_tablespace string UNDOTBS_1


SQL> select max(maxquerylen) from v$undostat;

MAX(MAXQUERYLEN)
----------------
35792

SQL>


run this based on threads in here:

SQL> select (35792/60)/60 query,(4200/60)/60 retention from dual;

QUERY RETENTION
---------- ----------
9.94222222 1.16666667


I need some help figuring out what to set my undo_retention to? Should it be 36000?

Any help is appreciated.

Thanks