Dbstl persistence  Direct database get Change persistence Object
life time and persistence  The following sections provide
information on how to achieve persistence using dbstl.  Direct
database get  Each container has a begin() method which produces
an iterator. These begin methods take a boolean parameter,
directdb_get, which controls the caching behavior of the
iterator. The default value of this parameter is true.  If
directdb_get is true, then the persistent object is fetched anew
from the database each time the iterator is dereferenced as a
pointer by use of the star-operator (*iterator) or by use of the
arrow-operator (iterator->member). If directdb_get is false,
then the first dereferencing of the iterator fetches the object
from the database, but later dereferences can return cached
data.  With directdb_get set to true, if you call:   then the
assignment to datamember1 will be lost, because the second
dereferencing of the iterator would cause the cached copy of the
object to be overwritten by the obj