ORA-12039: unable to use local rollback segment "string"

admin

ORA-12039: unable to use local rollback segment "string"
Cause: A local rollbacksegment was specified in the CREATE MATERIALIZED
VIEW command, but automatic refresh parameters were not specified. Therefore a
refresh group was not created to automatically refresh the materialized viewand
the local rollback segment can't be registered for future use.
Action: Either supply theautomatic refresh parameters so that a refresh group
will be created or do not specify a local rollback segment.