ORA-03190
Statement failure due to standby query SCN lag while reading undo segment string information.
Cause
A new undo segment is being added or an existing undo segment is being dropped on the primary database. A query can occasionally halt when issued around the time an undo segment is added, or dropped and used immediately on the primary.
Action
Retry the query. Review the reasons for the lagging query SCN on the standby database. Avoid frequent drop or creation of the new undo segments when using standby database.