title: MView "enable query rewrite" usage
body: <pre><code>CREATE TABLE TEST_DATE(COL1 VARCHAR2(20),COL2 NUMBER,COL3_DATE DATE,COL4_DATE DATE)
  /   
  
  create materialized view TEST_SYS
  REFRESH FORCE ON DEMAND
  ENABLE QUERY REWRITE  --- ????
  AS
  SELECT COL1,COL2
  FROM    TEST_date
  WHERE TRUNC(SYSDATE) BETWEEN TRUNC(COL3_DATE) AND TRUNC(COL4_DATE)
  /
  </code></pre>
  
  <p>If Enable Query Rewrite option is disabled, MView is getting created for the above query then what is the purpose of having ENABLE QUERY REWRITE clause while creating materialized view, can we remove it and create it, and do we have to compromise on the performance of the MView if we have to comment Enable Query Rewrite. </p>
  
  <p>Please explain me the use of enable query rewrite option in detail.</p>