Sacado de https://community.magento.com/t5/Technical-Issues/Cannot-initialize-the-indexer-process/td-p/21640

Open app/code/local/Sm/Shopby/Model/Resource/Indexer/Attribute.php

Around line 65 you will find the protected function called _getAttribute.

Change from this,

protectedfunction _getAttributes($attributeId =null){
        $collection =Mage::getSingleton('eav/config')
            ->getEntityType(Mage_Catalog_Model_Product::ENTITY)
            ->getAttributeCollection()
            ->addFieldToFilter('`main_table`.`frontend_input`', array('in'=> array('select','multiselect')));
        if(!empty($attributeId)){
            $collection->addFieldToFilter('`main_table`.`attribute_id`', $attributeId);
        }

        return $collection;
    }

to this code instead,

    protectedfunction _getAttributes($attributeId =null){
        $collection =Mage::getSingleton('eav/config')
            ->getEntityType(Mage_Catalog_Model_Product::ENTITY)
            ->getAttributeCollection()
            ->addFieldToFilter('main_table.frontend_input', array('in'=> array('select','multiselect')));
        if(!empty($attributeId)){
            $collection->addFieldToFilter('main_table.attribute_id', $attributeId);
        }

        return $collection;
    }

What changed?

The only thing I changed was removing the apostrophes (´) at lines 69 and 71. Which means that ´main_table´.´frontend_input' is now changed into main_table.frontend_input. Now the scripts updates SQL properly. Both in Admin and Shell.