Comment puis-je forcer Liquibase à recalculer les checksums sans relancer les instructions?

nous utilisons Liquibase 3.2 avec Java 6. Y a-t-il un moyen de forcer Liquibase à recalculer les checksums sans relancer les mêmes instructions à partir de nos fichiers Liquibase? Dans notre base de données, je gère ça ...

update DATABASECHANGELOG set md5sum = null where 1;

cependant, lorsque j'exécute mes scripts de modification Liquibase, certaines exécutions échouent toujours avec les erreurs suivantes ...

invoking liquibase change script with file /tmp/deploywork/db.changelog-master.xml
running /usr/java/liquibase/liquibase  --logLevel=info --driver=com.mysql.jdbc.Driver --classpath=/usr/java/jboss/modules/com/mysql/main/mysql-connector-java-5.1.22-bin.jar --changeLogFile=/tmp/deploywork/db.changelog-master.xml --url="jdbc:mysql://myservername:3306/my_db" --username=username --password=password update 
INFO 5/13/15 2:15 PM: liquibase: Successfully acquired change log lock
INFO 5/13/15 2:15 PM: liquibase: Reading from my_db.DATABASECHANGELOG
INFO 5/13/15 2:15 PM: liquibase: Successfully released change log lock
Unexpected error running Liquibase: Validation Failed:
     3 change sets check sum
          db.changelog-1.0.xml::1357593229391-25::rob (generated) is now: 7:5cfe9ecd779a71b6287ef2360a6979bf
          db.changelog-7.0.xml::create-address-email-index::davea is now: 7:da0132e30ebd6a1bc52d9a39bb8c56d7
          db.changelog-7.0.xml::add-myproject-event-object-id-col::davea is now: 7:2eab5d784647ce33ef3488aa8c383443


SEVERE 5/13/15 2:15 PM: liquibase: Validation Failed:
     3 change sets check sum
          db.changelog-1.0.xml::1357593229391-25::rob (generated) is now: 7:5cfe9ecd779a71b6287ef2360a6979bf
          db.changelog-7.0.xml::create-address-email-index::davea is now: 7:da0132e30ebd6a1bc52d9a39bb8c56d7
          db.changelog-7.0.xml::add-myproject-event-object-id-col::davea is now: 7:2eab5d784647ce33ef3488aa8c383443

liquibase.exception.ValidationFailedException: Validation Failed:
     3 change sets check sum
          db.changelog-1.0.xml::1357593229391-25::rob (generated) is now: 7:5cfe9ecd779a71b6287ef2360a6979bf
          db.changelog-7.0.xml::create-address-email-index::davea is now: 7:da0132e30ebd6a1bc52d9a39bb8c56d7
          db.changelog-7.0.xml::add-myproject-event-object-id-col::davea is now: 7:2eab5d784647ce33ef3488aa8c383443

    at liquibase.changelog.DatabaseChangeLog.validate(DatabaseChangeLog.java:181)
    at liquibase.Liquibase.update(Liquibase.java:191)
    at liquibase.Liquibase.update(Liquibase.java:174)
    at liquibase.integration.commandline.Main.doMigration(Main.java:997)
    at liquibase.integration.commandline.Main.run(Main.java:170)
    at liquibase.integration.commandline.Main.main(Main.java:89)

Ici est l'un des ensembles de modifications que le script est en plaindre ...

    <changeSet author="davea" id="add-myproject-event-object-id-col">
        <addColumn tableName="sb_myproject_event">
            <column name="OBJECT_ID" type="VARCHAR(32)"/>
        </addColumn>
        <createIndex indexName="SB_myproject_EVENT_IDX"
            tableName="sb_myproject_event"
            unique="false">
            <column name="OBJECT_ID" type="varchar(32)" />
        </createIndex>
        <sql>update sb_myproject_event set object_id=LEFT(SUBSTRING_INDEX(event_data, '&quot;id&quot;:&quot;', -2), 24) where object_id is null and event_data is not null;</sql>
        <!--  Delete older events that no longer need to be processed -->
        <sql>delete from sb_myproject_event where id not in (select q.* from (select e.id FROM sb_myproject_event e, (select object_id, max(date_processed) d from sb_myproject_event group by object_id) o where e.object_id = o.object_id and e.date_processed = o.d) q);</sql>
    </changeSet>

comme je l'ai dit, je veux seulement recalculez les totaux de contrôle (il faut le faire parce que nous changeons les versions de Liquibase).