title: Postgres UUID reference overhead
body: <p>Consider this table used to store object metadata</p>
  
  <pre><code>CREATE TABLE meta (
    "obj_uuid"  uuid,
    "type"      int,
    "value"     text
  );
  </code></pre>
  
  <p>Objects are identified using <code>uuid</code>s as primary keys, the metadata row references that <code>uuid</code>. Now I am concerned this will blow up the DB size exponentially.</p>
  
  <p>Does Postgres optimize this on itself, or would it be better to create an intermediate table that maps the <code>uuid</code> to a <code>serial</code> and reference this serial in the metadata table instead?</p>