title: Capture changes for the last 30 minutes from tables
body: <p>I need only to capture the changes for last 30 minutes only in for the below query:</p>
  
  <pre><code>  SELECT 
    P.COL1, P.COL2, P.COL3, C.COL1, C.COL2, T.COL1, T.COL2, P.COL4+T.COL4 AS "COL4"
    FROM
    TABLE1 P,
    TABLE2 C,
    TABLE3 T
    WHERE
    PM.COL1(+)  = C.COL1
    AND T.COL2(+) = C.COL2
  </code></pre>
  
  <p>TABLE 1, TABLE 2 AND TABLE3 each has a modification date column, but I think adding the following to the query logically won't be right and it might degrade the query execution performance</p>
  
  <pre><code> SELECT 
   P.COL1, P.COL2, P.COL3, C.COL1, C.COL2, T.COL1, T.COL2, P.COL4+T.COL4 AS "COL4" 
   FROM
   TABLE1 P,
   TABLE2 C,
   TABLE3 T
   WHERE
   PM.COL1(+)  = C.COL1
   AND T.COL2(+) = C.COL2
   AND P.MODIFICATION_DATE &gt; SYSDATE - 30
   AND C.MODIFICATION_DATE &gt; SYSDATE - 30 
   AND T.MODIFICATION_DATE &gt; SYSDATE - 30;
  </code></pre>
  
  <p>Also not all the 3 tables are updated at the same time, TABLE2 as an example last modification_date was yesterday at 11:00 am while TABLE3 modification_date is today at 2:00 pm.</p>
  
  <p>How can I capture the latest 30 minutes changes between the tables?</p>