@Test
  public void testExportMerge() throws Exception {
    int[][] rows1 = {{1, 2}, {3, 4}};
    runStatementOnDriver("drop table if exists T");
    runStatementOnDriver("drop table if exists TImport ");
    runStatementOnDriver("create table T (a int, b int) stored as ORC");
    runStatementOnDriver("create table TImport (a int, b int) stored as ORC TBLPROPERTIES " +
        "('transactional'='false')");
    runStatementOnDriver("insert into T(a,b) " + makeValuesClause(rows1));
    runStatementOnDriver("update T set b = 17 where a = 1");
    int[][] rows2 = {{1, 17}, {3, 4}};
    List<String> rs = runStatementOnDriver("select * from T order by a,b");
    Assert.assertEquals("Content didn't match rs", stringifyValues(rows2), rs);

    String exportStmt = "export table T to '" + getTestDataDir() + "/export'";
    rs = runStatementOnDriver("explain " + exportStmt);
    StringBuilder sb = new StringBuilder("*** " + exportStmt);
    for (String r : rs) {
      sb.append("\n").append(r);
    }
    LOG.error(sb.toString());

    runStatementOnDriver(exportStmt);
    //verify data
    runStatementOnDriver("import table TImport from '" + getTestDataDir() + "/export'");
    List<String> rs1 = runStatementOnDriver("select * from TImport order by a, b");
    Assert.assertEquals("Content didn't match rs", stringifyValues(rows2), rs1);
  }
The update delete cause MergeFileTask to be executed.
ql/src/test/org/apache/hadoop/hive/ql/TestTxnExIm.java