java - Persisting time ojects as entities instead of value types? -

i'm using joda time datetime handle date , time. persist objects of kind using class persistentdatetime bundled in jodatime hibernate code.

i have large collections of datetime objects, , persist them in following way (an excerpt of hibernate mapping file follows):

<set name="validinstants" sort="natural">      <key column="myobject_id"/>      <element column="date" type="myproject.utilities.hibernate.types.persistentdatetime"/>  </set> 

doing so, i.e. storing datetimes value types, many duplicate elements in table validinstants, hundreds of thousands of them. i'd avoid , have in validinstants table datetimes needed, stored once per value. how can achieve this?

as far know (i'm , hibernate beginner) way achieve creating class wraps datetime , maps entity, plus creating factory returns same datetime-wrapper when asking same date. best way want? suggestions?

what relationship between entity being stored here , validinstants set? entity "own" validinstants? member of validinstants have use or life outside of entity declared part of?

if not, don't think makes sense treat non-entity entity (which you'd doing if "creating class wraps datetime , maps entity").

i not worry having many duplicate elements in table storing these dates, unless it's proven large problem. indexing on myobject_id column, these lookups should fast enough.