title: Mysql Bigint VS Varchar
body: <p>What is the best for index field, and space token on hard disk/RAM? Biginteger or Varchar(15) ?
  I can have for example such index number:</p>
  
  <pre><code>from  10000001 to 45281229703 and higher...
  </code></pre>
  
  <p>But what is better to choose?
  Also on non-indexing field what field type is better?</p>