public Filter createSpanQualifierFilter() {
        byte indexPrefix = SpanEncoder.TYPE_SPAN;
        ByteArrayComparable prefixComparator = new BinaryPrefixComparator(new byte[]{indexPrefix});
        return new QualifierFilter(CompareOperator.EQUAL, prefixComparator);
    }
@author Woonduk Kang(emeroad)
@author Taejin Koo
web/src/main/java/com/navercorp/pinpoint/web/dao/hbase/HbaseTraceDaoV2.java