title: ERROR: could not read block 4707 of relation 1663/16384/16564: Success
body: <p>I am using psql 8.1.18 on Glassfishserver. I have a query like this:</p>
  
  <pre><code>select ip,round((select sum(t1.size) from table t1)) 
  from table 
  where date &gt; '2011.07.29' 
  and date &lt; '2011.07.30' 
  and ip = '255.255.255.255' 
  group by ip;
  </code></pre>
  
  <p>When I run this query I got this error:</p>
  
  <pre><code>ERROR:  could not read block 4707 of relation 1663/16384/16564: Success
  </code></pre>
  
  <p>However this query works fine:</p>
  
  <pre><code>select ip,round(sum(size)/175) 
  from table 
  where date &gt; '2011.07.29' 
  and l_date &lt; '2011.07.30' 
  and ip = '255.255.255.255' 
  group by ip;
  </code></pre>
  
  <p>I think it might be a database error and I need to restore the table from the backup, maybe. But first I need to learn where this corrupted data exist. Does anyone know how to find 1663/16384/16564 relation? Or 4707 block?  </p>
  
  <p>EDIT:
  I tried this code:</p>
  
  <pre><code>select relname , relfilenode from pg_class where  relname in ('1663','16384','16564');
  </code></pre>
  
  <p>but it returns:</p>
  
  <pre><code>relname | relfilenode 
  ---------+-------------
  (0 rows)
  </code></pre>