title: Find definition of type in PostgreSQL
body: <p>I have such DDL of tables from PostgreSQL:</p>
  
  <pre><code>CREATE TABLE some_table (
      id identifier NOT NULL DEFAULT nextval('some_table_id_seq'),
      center_name common_name NULL,
      ...
  )
  </code></pre>
  
  <p>Those <code>identifier</code> and <code>common_name</code> types are not standart PostgreSQL types. How to find their definitions?</p>