I have the following schema in my hbm.xml file
<hibernate-mapping>
<class name="com.beans.MyTemplate" table="MyTemplate">
<composite-id name="key" class="com.beans.MyTemplatePk">
<key-property name="dataStoreId"/>
<key-property name="name"/>
</composite-id>
<discriminator column="advanced" type="string"/>
<property name="reportType"/>

<subclass name="com.beans.SatReport" discriminator-value="A">
<property name="includeTableForAllGraphs"/>

<list name="fileSizeBucketList" cascade="save-update" lazy="false">
<key not-null="true">
<column name="dataStoreId" />
<column name="name"/>
</key>
<list-index column="sortOrder"/>
<many-to-many class="com.beans.TierBucket" column="key"/>
</list>

<list name="satReportSelections" cascade="all-delete-orphan" lazy="false">
<key not-null="true">
<column name="dataStoreId" not-null="true"/>
<column name="name" not-null="true"/>
</key>
<list-index column="sortOrder"/>
<composite-element class="com.beans.SatReportSelection">
<property name="key"/>
<property name="selected"/>
</composite-element>
</list>
</subclass>
<subclass name="com.beans.SatBatReport" discriminator-value="C">
<property name="npv"/>
<property name="chartStyle" type="string" not-null="true">
<column name="chartStyle" default="'Color Fill'"/>
</property>
<list name="fileAgeBucketList" cascade="save-update" lazy="false">
<key not-null="true">
<column name="dataStoreId" />
<column name="name"/>
</key>
<list-index column="sortOrder"/>
<many-to-many class="com.beans.TierBucket" column="key"/>
</list>
<list name="satReportSelections" cascade="all-delete-orphan" lazy="false">
<key not-null="true">
<column name="dataStoreId" not-null="true"/>
<column name="name" not-null="true"/>
</key>
<list-index column="sortOrder"/>
<composite-element class="com.beans.SatReportSelection">
<property name="key"/>
<property name="selected"/>
</composite-element>
</list>
</subclass>
</class>
</hibernate-mapping>

The two subclasses SatReport and SatBatReport have the same lists fileSizeBucketList and satReportSelections. I see the following error messages in the log file.

2009-05-07 13:52:37,157 ERROR hbm2ddl.SchemaUpdate: Unsuccessful: alter table fileAgeBucketList add constraint FKCCF1CFEB36E6E9B2 foreign key (dataStoreId, name) references MyTemplate
2009-05-07 13:52:37,157 ERROR hbm2ddl.SchemaUpdate: Constraint already exists in statement [alter table fileAgeBucketList add constraint FKCCF1CFEB36E6E9B2 foreign key (dataStoreId, name) references MyTemplate]
2009-05-07 13:52:37,157 ERROR hbm2ddl.SchemaUpdate: Unsuccessful: alter table satReportSelections add constraint FK54CF74C136E6E9B2 foreign key (dataStoreId, name) references MyTemplate
2009-05-07 13:52:37,157 ERROR hbm2ddl.SchemaUpdate: Constraint already exists in statement [alter table satReportSelections add constraint FK54CF74C136E6E9B2 foreign key (dataStoreId, name) references MyTemplate]

Any idea how to avoid these error messages? Saving and retrieving objects seem to work fine.

Thanks,
Bindu