title: Multidimensional Tables in PostgreSQL
body: <p>I have been wondering whether it's possible to do multidimensional tables in PostgreSQL. Here's an example table from my project:</p>
  
  <pre><code>     id |  created_by   |          content           | comments |   
       ---+---------------+----------------------------+----------+
        1 | Anonymous     | does this thing work?      |          | 
        2 | James         | this is the body           |          | 
        3 | Chan          | this must work this time~! |          | 
        4 | Freak         | just to add something new  |          | 
        5 | Anonymous     | yahoo!                     |          | 
  </code></pre>
  
  <p>What do I mean by multidimensional table? It would look like something like this if there's such thing.</p>
  
  <pre><code>     id |  created_by   |          content           |             comments                     |   
       ---+---------------+----------------------------+------------------------------------------+
        1 | Anonymous     | does this thing work?      | id | created_by |         comments       | 
        2 | James         | this is the body           |                 |created_by|   comments  | 
        3 | Chan          | this must work this time~! |                                  | 
        4 | Freak         | just to add something new  |                                  | 
        5 | Anonymous     | yahoo!                     |                                  | 
  </code></pre>
  
  <p>This is just an example. But the key concept is that in every comment, there's another set of columns, making comments sort of like a table by itself.</p>
  
  <p>So yeah, does this exist in Postgres or is there any better way to implement this feature? :)</p>