Why attributes of bundle items of a bundle product are also saved to the bundle product itself? (database-wise)

Update: how to stop the indexer from including child products

1. Extend and modify Mage_Catalog_Model_Resource_Product_Indexer_Eav_Abstract.
2. Look for the function _prepareRelationIndex().
3. Modify the SQL query builder statement as follows:

Code:

$select = $write->select()
    ->from(array('l' => $this->getTable('catalog/product_relation')), 'parent_id')
    ->join(
        array('cs' => $this->getTable('core/store')),
        '',
        array())
    ->join(
        array('i' => $idxTable),
        'l.child_id = i.entity_id AND cs.store_id = i.store_id',
        array('attribute_id', 'store_id', 'value'))
    ->join(
        array('e' => 'catalog_product_entity'),
        'l.parent_id = e.entity_id',
        array())
    ->group(array(
        'l.parent_id', 'i.attribute_id', 'i.store_id', 'i.value'
    ))
    ->where('e.type_id != ?', 'bundle');

_{reference: addition of codes highlighted in red}

It is the same way with configurable products.

If you are looking for white shoes and the configurable products solves this problem for you, the product is offered. I think it is easy as this. So if your searched product is part of a bundle product, this product is offered too.