@Override
        public RSIndex create(byte dataType, ByteSlice buffer, int packCount) {
            assert ColumnType.isNumber(dataType);
            return new RSIndex_Histogram(buffer, packCount, ColumnType.isFloatPoint(dataType));
        }
Each pack (with 65536 values), we use 128 bytes, i.e. 1024 bits to index.
indexr-segment/src/main/java/io/indexr/segment/index/RSIndex_Histogram.java