Function OptimalNumOfBytes

cpp/src/parquet/bloom_filter.h:236–240

Calculate optimal size according to the number of distinct values and false positive probability. @param ndv The number of distinct values. @param fpp The false positive probability. @return it always return a value between kMinimumBloomFilterBytes and kMaximumBloomFilterBytes, and the return value is always a power of 2

  /// @return it always return a value between kMinimumBloomFilterBytes and
  /// kMaximumBloomFilterBytes, and the return value is always a power of 2
  static uint32_t OptimalNumOfBytes(uint64_t ndv, double fpp) {
    uint32_t optimal_num_of_bits = OptimalNumOfBits(ndv, fpp);
    ARROW_DCHECK(::arrow::bit_util::IsMultipleOf8(optimal_num_of_bits));
    return optimal_num_of_bits >> 3;
  }

  /// Calculate optimal size according to the number of distinct values and false
  /// positive probability.