title: SQL Server data types: Store 8-digit unsigned number as INT or as CHAR(8)?
body: <p>i think the title says everything.
  Is it better(faster,space-saving according memory and disk) to store 8-digit unsigned numbers as Int or as char(8) type?
  Would i get into trouble when the number will change to 9 digits in future when i use a fixed char-length?</p>
  
  <p>Background-Info: i want to store <a href="http://en.wikipedia.org/wiki/Type_Allocation_Code" rel="nofollow">TAC</a>s</p>
  
  <p>Thanks</p>