title: SQL Best Practices - Ok to rely on auto increment field to sort rows chronologically?
body: <p>I'm working with a client who wants to add timestamps to a bunch of tables so that they may sort the records in those tables chronologically.  All of the tables also have an auto incrementing integer field as their primary key (id).</p>
  
  <p>The (simple) idea - save the overhead/storage and rely on the primary key to sort fields chronologically.  Sure this works, but I'm uncertain whether or not this approach is acceptable in sound database design.</p>
  
  <p>Pros:  less storage required per record, simpler VO classes, etc. etc.</p>
  
  <p>Con: it implies a characteristic of that field, an otherwise simple identifer, whose definition does not in any way define or guarantee that it should/will function as such.</p>
  
  <p>Assume for the sake of my question that the DB table definitions are set in stone.  Still - is this acceptable in terms of best practices?</p>
  
  <p>Thanks</p>