title: Oracle delete from query hanging on a very small dataset
body: <p>Hello I'm trying to run a delete from statement in sqlplus using oracle 11g. It was working fine, because every time I test my program I need to delete a few thousand rows, to test it again and this is just the nature of the program. However, it suddenly stopped deleting the rows and simply hangs now. I'm not sure why.</p>
  
  <pre><code>SQL&gt; explain plan for delete from ip_address_usages where datetime= '30-SEP-14 22:44:00';
  
  Explained.
  
  SQL&gt; SELECT * 
  FROM   TABLE(DBMS_XPLAN.DISPLAY);  2  
  
  PLAN_TABLE_OUTPUT
  ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Plan hash value: 250311489
  
  ----------------------------------------------------------------------------------------
  | Id  | Operation          | Name              | Rows  | Bytes | Cost (%CPU)| Time     |
  ----------------------------------------------------------------------------------------
  |   0 | DELETE STATEMENT   |                   |  2295 | 39015 |     7   (0)| 00:00:01 |
  |   1 |  DELETE            | IP_ADDRESS_USAGES |       |       |            |          |
  |*  2 |   TABLE ACCESS FULL| IP_ADDRESS_USAGES |  2295 | 39015 |     7   (0)| 00:00:01 |
  ----------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - filter("DATETIME"=TO_TIMESTAMP('30-SEP-14 22:44:00'))
  
  14 rows selected.
  
  SQL&gt; delete from ip_address_usages where datetime= '30-SEP-14 22:44:00';
  </code></pre>
  
  <p>20 minutes later still sitting there hasn't changed.</p>