presto-orc/src/main/java/io/prestosql/orc/reader/SliceColumnReader.java/SliceColumnReader/getRetainedSizeInBytes
class SliceColumnReader:    @Override
    public long getRetainedSizeInBytes()
    {
        return INSTANCE_SIZE + directReader.getRetainedSizeInBytes() + dictionaryReader.getRetainedSizeInBytes();
    }