title: Optimizing a LINQ query
body: <p>I have a LINQ query that is returning the results and format I desire, but it seems a bit slow. Wondering if there is a way to improve its performance? The <code>Items</code> and <code>Skus</code> records are 1:1. For each <code>Item</code> there 5 <code>ItemWhse</code> and 5 <code>SkuWhse</code> records for each <code>Skus</code> record.</p>
  <pre><code>var orderItems = from item in db.Items
              join sku in db.Skus
                  on item.Sku equals sku.Sku
              where item.OrderNumber == 12345678
              select new
              {
                  Item = item,
                  ItemWhse = from itemWhse in db.ItemWarehouse
                            where itemWhse.OrderNumber == item.OrderNumber
                              &amp;&amp; itemWhse.LineNumber == item.LineNumber
                            select itemWhse,
                  Sku = sku,
                  SkuWhse = from skuWhse in db.SkuWarehouse
                              where skuWhse.Sku == sku.Sku
                              select skuWhse
              };
  </code></pre>