title: google sitemap need all article in site or indexing latest only?
body: <p>Right now we have sitemap that produced dynamicly with around 400 products and submit it in google sitemap for index purpose. It's always hit the server resource to produce xml format for 400 products each time google sitemap crawl it. Since most product already indexed by google, I'm thingking to reduce the dynamic sitemap to only generate latest 50 products to save server resource. </p>
  
  <p>I'm search an explanation about does google sitemap need all products to index regularly or just need the latest product that not indexed yet? Please advise me about this.</p>