title: Update table content based on table with same columns with some kind of table delta
body: <p>I have an application &quot;A&quot; which is installed on over 100 different machines. In this application there is a table with around 400'000 articles. Each day these articles get updated on a different application &quot;B&quot;. Now I copy the updated table from &quot;B&quot; to each installation of &quot;A&quot; and end up there with two tables (articles (old content) and master_articles (new content)). Then I want to update my articles table with the content of the master_articles. Of course I could just delete the content from articles and move all the content from master_articles into it. But is there some way to calculate the delta of these two tables and just (update the rows which changed / delete the rows which doesn't exist in master_articles / insert the rows which are not part of the articles table). It is just to get a better performance.</p>
  <p>Thanks in advance for your answers</p>