XML : How to efficiently mass update?

I'm working on an integration with our warehouse. We receive an XML message with all our SKUs and their inventory levels. For each SKU I need to update the inventory level in my rails app. However, every time I request the XML message, the processing is very slow, to the point where the browser times out. I suspect this is because I have to do a look up for each SKU by name and update the inventory level for it. There should be around 1000 SKUs returned in the XML, this means 2 lookups for each SKU and 1 save.

Is there a way for me to optimize the performance for this integration? I am fairly new to Rails but I feel like there should be a more efficient way of doing this.

Example XML:

  <InventoryXML>  <Item>     <ItemID>ABC-12-2345</ItemID>     <ItemQty>14</ItemQty>     <Warehouses>      <Warehouse>         <Name>Constitution</Name>        <Quantity>9</Quantity>       </Warehouse>      <Warehouse>         <Name>Vegas</Name>        <Quantity>1</Quantity>       </Warehouse>      <Warehouse>         <Name>Atlanta</Name>        <Quantity>4</Quantity>       </Warehouse>    </Warehouses>   </Item>  </InventoryXML>    

Code:

  def process_inventory      @doc.xpath('//Item').each do |item|          name = item.xpath('//ItemID').text          warehouses = item.xpath('//Warehouses')          warehouses.xpath('Warehouse').each do |warehouse|              if warehouse.xpath('Name').text == "Vegas"                  self.update_inventory_for_sku(2, name, warehouse.xpath('Quantity').text.to_i)              elsif warehouse.xpath('Name').text == "PA"                  self.update_inventory_for_sku(1, name, warehouse.xpath('Quantity').text.to_i)              end          end      end      return "Succesfully updated SKU inventory"  end    def update_inventory_for_sku(vendor_id, name, quantity)      sku = VendorSku.where({vendor_id: vendor_id, name: name}).first      if sku          sku.update_attributes(inventory_quantity: quantity)      else          self.hub_error_message += "\nSKU not found: " + name.to_s + "for vendor_id: " + vendor_id.to_s      end  end