ora-1555

Hi All,

I would appreciate if someone can guide me with sql script and steps to troubleshoot below error:

ORA-01555 caused by SQL statement below (SQL ID: 8wqkdyghz15544, Query Duration=2019 sec, SCN: 0x0001.88c9a280):

ORA-01555: snapshot too old: rollback segment number ORA-01555: snapshot too old: rollback segment number  with name "" too small
ORA-06512: at "SYS.DBMS_STATS", line 13591
ORA-06512: at "SYS.DBMS_STATS", line 13937
ORA-06512: at "SYS.DBMS_STATS", line 14015
ORA-06512: at "SYS.DBMS_STATS", line 13974
ORA-06512: at line 1
 with name "" too small
will it help by bumping up undo_retentin?how we can calculate exact size?

Regars

Regars