protected function addObjectIdentitiesTable()
    {
        $table = $this->createTable($this->options['oid_table_name']);

        $table->addColumn('id', 'integer', array('unsigned' => true, 'autoincrement' => true));
        $table->addColumn('class_id', 'integer', array('unsigned' => true));
        $table->addColumn('object_identifier', 'string', array('length' => 100));
        $table->addColumn('parent_object_identity_id', 'integer', array('unsigned' => true, 'notnull' => false));
        $table->addColumn('entries_inheriting', 'boolean');

        $table->setPrimaryKey(array('id'));
        $table->addUniqueIndex(array('object_identifier', 'class_id'));
        $table->addIndex(array('parent_object_identity_id'));

        $table->addForeignKeyConstraint($table, array('parent_object_identity_id'), array('id'));
    }