final String segmentBitmapSerdeFactoryString = mapper.writeValueAsString(segmentBitmapSerdeFactory);
final long numBytes = cols.getSerializedSize() + dims9.getSerializedSize() + 16
+ serializerUtils.getSerializedStringByteSize(segmentBitmapSerdeFactoryString);
final SmooshedWriter writer = v9Smoosher.addWithSmooshedWriter("index.drd", numBytes);
cols.writeToChannel(writer);
dims9.writeToChannel(writer);
serializerUtils.writeLong(writer, dataInterval.getStartMillis());
serializerUtils.writeLong(writer, dataInterval.getEndMillis());
serializerUtils.writeString(writer, segmentBitmapSerdeFactoryString);