title: What's the difference between pg_table_size, pg_relation_size & pg_total_relation_size? (PostgreSQL)
body: <p>What's the difference between <code>pg_table_size()</code>, <code>pg_relation_size()</code> &amp; <code>pg_total_relation_size()</code>?</p>
  
  <p>I understand the basic differences explained <a href="https://www.postgresql.org/docs/current/static/functions-admin.html#FUNCTIONS-ADMIN-DBSIZE" rel="noreferrer">in the documentation</a>, but what does it imply in terms of how much space my table is actually using?</p>