title: Is this a postgresql bug? Only one row can not query by equal but can query by like
body: <p>i have a table,only one row in this table can not query by equal query,but can query by like (not incloud %).</p>
  
  <p>postgresql server version:90513 </p>
  
  <pre class="lang-sql prettyprint-override"><code># select id,external_id,username,external_id from users where username = 'oFIC94vdidrrKHpi5lc1_2Ibv-OA';
   id | external_id | username | external_id 
  ----+-------------+----------+-------------
  (0 rows)
  
  # select id,external_id,username,external_id from users where username like 'oFIC94vdidrrKHpi5lc1_2Ibv-OA';
                    id                  |         external_id          |           username           |         external_id          
  --------------------------------------+------------------------------+------------------------------+------------------------------
   61ebea19-74f5-4713-9a30-63eb5af8ac8f | oFIC94vdidrrKHpi5lc1_2Ibv-OA | oFIC94vdidrrKHpi5lc1_2Ibv-OA | oFIC94vdidrrKHpi5lc1_2Ibv-OA
  (1 row)
  
  </code></pre>
  
  <p>if i dump this table and restore it,it will be fixed. by why.</p>
  
  <p>it is a postgresql bug? how can i workaround it. I've met twice.</p>