Class: FastExists::Optimizer::AiAdvisor

Inherits:
Object
  • Object
show all
Defined in:
lib/fast_exists/optimizer/ai_advisor.rb

Class Method Summary collapse

Class Method Details

.analyze(model_class = nil, attribute = nil) ⇒ Object 



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# File 'lib/fast_exists/optimizer/ai_advisor.rb', line 6

def self.analyze(model_class = nil, attribute = nil)
  stats = FastExists.stats
  db_count = model_class ? (model_class.count rescue 100_000) : 100_000

  recommended_fp = stats[:false_positive_rate] > 0.01 ? 0.001 : 0.0005
  recommended_capacity = (db_count * 1.5).ceil

  # Optimal m calculation: m = - (n * ln(p)) / (ln(2)^2)
  optimal_bits = (-(recommended_capacity * Math.log(recommended_fp)) / (Math.log(2)**2)).ceil
  optimal_hashes = [((optimal_bits.to_f / recommended_capacity) * Math.log(2)).round, 1].max

  recommended_backend = case db_count
                        when 0..100_000 then :memory
                        when 100_001..5_000_000 then :redis
                        else :redis_bloom
                        end

  {
    current_stats: stats,
    recommendations: {
      false_positive_rate: recommended_fp,
      expected_elements: recommended_capacity,
      optimal_bit_size: optimal_bits,
      optimal_hash_count: optimal_hashes,
      recommended_backend: recommended_backend,
      estimated_memory_mb: (optimal_bits / 8.0 / 1_048_576.0).round(2),
      advice: generate_advice(stats, db_count, recommended_backend)
    }
  }
end

.generate_advice(stats, db_count, backend) ⇒ Object 



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# File 'lib/fast_exists/optimizer/ai_advisor.rb', line 39

def self.generate_advice(stats, db_count, backend)
  adv = []
  if stats[:false_positive_rate] > 0.01
    adv << "False positive rate is high (#{stats[:false_positive_rate] * 100}%). Increase expected_elements or reduce false_positive_rate target."
  end
  if stats[:hit_ratio] > 0.8
    adv << "High Bloom filter hit ratio (#{stats[:hit_ratio] * 100}%). Most lookups are positive. Check if existence queries are necessary before writing."
  end
  adv << "Recommended backend for dataset of #{db_count} records is :#{backend}."
  adv.join(" ")
end