Hi guys you can check in your database when you faced Snapshot too old error for undo tablespace since your database started. Its showing here '0' it means we have not faced this issue.
SQL> select 'Number of "ORA-01555 (Snapshot too old)" encountered since the last startup of the instance : ' || sum(ssolderrcnt) from v$undostat;
'NUMBEROF"ORA-01555(SNAPSHOTTOOOLD)"ENCOUNTEREDSINCETHELASTSTARTUPOFTHEINSTANCE:'||SUM(SSOLDERRCNT)
------------------------------------------------------------------------------------------------------------------------------------
Number of "ORA-01555 (Snapshot too old)" encountered since
the last startup of the instance : 0
Happy Learning....
