@Test
  public void testNoFilter() throws Exception {
    // No filter
    long expectedRows = this.numRows;
    long expectedKeys = this.colsPerRow;

    // Both families
    Scan s = new Scan();
    verifyScan(s, expectedRows, expectedKeys);

    // One family
    s = new Scan();
    s.addFamily(FAMILIES[0]);
    verifyScan(s, expectedRows, expectedKeys / 2);
  }
Test filters at the HRegion doorstep.
hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestFilter.java