title: database design - when to split tables?
body: <p>Sometimes creating a separate table would produce much more work, should I split it anyway?</p>
  
  <p><strong>for example:</strong> In my project I have a table of customers, <strong>each customer has his own special price for each product</strong> (there are only 5 products &amp; more products are not planned in the future), each customer also have unique days of the week when the company delivers to him the products. </p>
  
  <p>Many operations like changing days/price for a customer, or displaying days &amp; prices of all customers would be much easier when the days &amp; product prices are columns in the customers table and not separate tables, so is it refuted to create only one big customers table in such case? What are the drawbacks?</p>
  
  <p><strong>UPDATE:</strong> They just informed me that after a year or so there's a chance that they add more products, they say their business won't exceed 20-30 products in any event.
  I still can't understand why in such case when product's prices has no relation (each customer has his own special price) adding rows to Products table is better then adding Columns to Customers table?
  The only benefit I could think of is that customer that has only 5 products won't have to 'carry' 20 nullable products (saves space on server)? I don't have much experience so maybe I'm missing the obvious?</p>