Magento Indexer – Adding Custom Attribute to Flat Table

Magento Not adding custom Attribute to flat table…..
I have a market place extension…which have some attribute but some attributes not adding to flat table…due to my extension not working….

attribute setting is…

$catalogEavSetup->addAttribute(Mage_Catalog_Model_Product::ENTITY, 'approval', array(
    'group' => 'General',
    'sort_order' => 21,
    'type' => 'int',
    'backend' => '',
    'frontend' => '',
    'label' => 'Approval',
    'note' => '',
    'input' => 'select',
    'class' => '',
    'source' => 'vendorsproduct/source_approval',
    'global' => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL,
    'visible' => true,
    'required' => false,
    'user_defined' => false,
    'default' => '1',
    'visible_on_front' => false,
    'unique' => false,
    'is_configurable' => false,
    'used_for_promo_rules' => false,
    'used_in_product_listing'  => true,
));

whole setting is correct..but due to mysql limit 65536…some attributes is not adding to flat tables…
I need to know that how to add these attribute in flat tables…