title: Postgresql record to array
body: <p>I need to convert from an array to rows and back to an array for filtering records.
  I'm using <strong>information_schema._pg_expandarray</strong> in a SELECT query to get one row per value in the array.</p>
  
  <p>Given the following array :</p>
  
  <pre><code>"char"[]
  {i,i,o,t,b}
  </code></pre>
  
  <p>_pg_expandarray retuns 5 rows with 1 column of type record :</p>
  
  <pre><code>record
  (i,1)
  (i,2)
  (o,3)
  (t,4) &lt;= to be filtered out later
  (b,5)
  </code></pre>
  
  <p>I need to filter this result set to exclude record(s) that contains <strong>'t'</strong>.</p>
  
  <p>How can I do that ? Should I convert back to an array ?
  Is there a way to filter on the array directly ?</p>
  
  <p>Thanks in advance.</p>