Magento: Overriding Model

<config>
<global>
<models>
<review_mysql4>
<rewrite>
<review>Globe_Review_Model_Mysql4_Review</review>
</rewrite>
</review_mysql4>
<review>
<rewrite>
<review>Globe_Review_Model_Review</review>
</rewrite>
</review>
</models>
</global>
<frontend>
<routers>
<review>
<args>
<modules>
<Globe_Review before="Mage_Review">Globe_Review</Globe_Review>
</modules>
</args>
</review>
</routers>
</frontend>
</config>

Reference:
Magento overriding core files blocks models resources controllers