title: Delete huge data - truncate partition programmatically
body: <p>As described in this <a href="https://stackoverflow.com/questions/38529364/should-i-partition-subpartition-my-table">question</a>, I have the follow table:</p>
  
  <pre><code>create table prova_log(
         id_dispositive       number,
         type                 number,
         date_verification    date,
         status               number
  )
  partition by range (date_verification) interval (numtoyminterval(1,'MONTH'))
  subpartition by list (type)  
  subpartition TEMPLATE (
      SUBPARTITION type1 VALUES (1),
      SUBPARTITION type2 VALUES (2),
      SUBPARTITION type3 VALUES (3),
      SUBPARTITION type4 VALUES (4)
  )                          
  (
     partition p0816 values less than (to_date('01/09/2016','dd/mm/yyyy'))
  );
  </code></pre>
  
  <p>As you can see, I named the first partition as <strong>p0816</strong>. But the next partitions will be generated with a random name right?</p>
  
  <p>I need to purge the table programmatically within an oracle job.
  I was thinking - as my scenario is to deal with 1B rows/month - to drop a partition. But how can I do that? How to find out a table partition by date ranges?</p>
  
  <p>I want to do something like:</p>
  
  <p><code>alter table prova_log drop partition XPTO</code></p>
  
  <p>"XPTO" would be a random partition name, but selected by date range - lets say 3 months before. In other words, delete everything before 2016/08/01</p>