title: Database partitioning - Horizontal vs Vertical - Difference between Normalization and Row Splitting?
body: <p>I am trying to grasp the different concepts of <em>Database Partitioning</em> and this is what I understood of it:</p>
  
  <p><strong>Horizontal Partitioning/Sharding</strong>: Splitting a table into different table that will contain a subset of the rows that were in the initial table (an example that I have seen a lot if splitting a Users table by Continent, like a sub table for North America, another one for Europe, etc...). Each partition being in a different <strong>physical location</strong> (understand 'machine').
  As I understood it, Horizontal Partitioning and Sharding are the exact same thing(?).</p>
  
  <p><strong>Vertical Partitioning</strong>: From what I understood (<a href="http://technet.microsoft.com/en-us/library/ms178148%28v=sql.105%29.aspx" rel="noreferrer">http://technet.microsoft.com/en-us/library/ms178148%28v=sql.105%29.aspx</a> ), there are 2 sorts of Vertical Partitioning:</p>
  
  <ul>
  <li><p><em>Normalization</em> (which consists of removing redundancies from a the database by splitting tables and linking them with a foreign key). </p></li>
  <li><p><em>Row Splitting</em>, here is what I don't understand, what is the difference between <em>Normalization</em> and <em>Row Splitting</em>? In what those 2 techniques differ from each other?</p></li>
  </ul>
  
  <p>I have also read in this post (<a href="https://stackoverflow.com/questions/11707879/difference-between-scaling-horizontally-and-vertically-for-databases">Difference between scaling horizontally and vertically for databases</a> ) that the difference between Horizontal Partitioning and Vertical Partitioning is that in the first you scale by adding more machines, while in the second one you scale by adding more power (CPU, RAM) to your existing machine, is that a correct definition? I thought that the <strong><em>core</em></strong> difference between those 2 techniques resides in the way you split your tables.</p>
  
  <p>I am sorry for the load of questions but I am a bit confused as a lot of different websites that I have came across say different things.</p>
  
  <p>Any help clarifying would be greatly appreciated. Any link to a clear and simple demonstration with a few tables would also be very helpful.</p>