I have a table USER. A USER can have many possible types. These possible types are in a lookup table USER_TYPE I would like to keep that association in Hibernate by creating a Hibernate POJO for USER_TYPE. But the problem is that whenevre the there is an access to either:

the getType() of the User object or

the equals and hashcode methods (type is a property of the user which uniquely defines it)

There is a SQL generated to access the DB. IS there any way to avoid/cache this since this information (the UserType) always has the same values

Hibernate version:
3.0

Mapping documents:

Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:

Name and version of the database you are using:

The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:


Problems with Session and transaction handling?

Read this: http://hibernate.org/42.html

This sounds like a many-to-one relationship. What are your mapping files for user and user_type?

User.hbm.xml:

<hibernate-mapping>
<class name="com.gen.User" table="USER" catalog="gen">
<id name="identityId" type="java.lang.Integer">
<column name="IDENTITY_ID" />
<generator class="native" />
</id>
<many-to-one name="typeOf" class="com.gen.UserType" fetch="select">
<column name="USER_TYPE_ID" />
</many-to-one>
... ...
</class>
</hibernate-mapping>


UserType.hbm.xml

<hibernate-mapping>
<class name="com.gen.UserType" table="USER_TYPE" catalog="gen">
<id name="USER_TYPE" type="java.lang.Integer">
<column name="USER_TYPE_ID" />
<generator class="native" />
</id>

<property name="name" type="java.lang.String">
<column name="TYPE_NAME" not-null="true" />
</property>
... ...
</class>
</hibernate-mapping>

Will your UserType class ever change? If not, you can make the class immutable using mutable="false" and make the cache a read-only cache. Refer to
file:///apps/hibernate-3.2/doc/reference/en/html_single/index.html#performance-cache-readonly

Thanks. Thats useful but requires the secodn level cache to be switched on-which I know is very useful. But is there a way to acheive the same result with only the session cache?

Havent tried that but can you just do the mutable="false" and try. Hibernate docs indicate that it does some performance optimizations if the mutable attribute is set to false.