Module: ActiveRecord::ConnectionAdapters::ClickHouse::RelationCalculations

Defined in:
lib/active_record/connection_adapters/clickhouse/querying.rb

Overview

Terminal calculations over ClickHouse's aggregate-function library; separate from RelationMethods because these execute immediately rather than build state. All accept merge: true (-Merge, finishing AggregateFunction state columns) and if: condition (-If, per-row conditional aggregation in a single scan); if is a Ruby keyword, so it travels in **options.

Instance Method Summary collapse

Instance Method Details

#arg_max(column, criterion, **options) ⇒ Object 



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 339

def arg_max(column, criterion, **options)
  aggregate("argMax", [klass.arel_table[column], klass.arel_table[criterion]], condition: options[:if])
end

#arg_min(column, criterion, **options) ⇒ Object 



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 343

def arg_min(column, criterion, **options)
  aggregate("argMin", [klass.arel_table[column], klass.arel_table[criterion]], condition: options[:if])
end

#estimated_count ⇒ Object

Table-level row estimate from metadata — O(1), ignores relation scopes.



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 348

def estimated_count
  klass.with_connection do |connection|
    connection.select_value(<<~SQL.squish, "#{klass.name} Estimated Count").to_i
      SELECT total_rows FROM system.tables
      WHERE database = currentDatabase() AND name = #{connection.quote(klass.table_name)}
    SQL
  end
end

#quantile(fraction, column, merge: false, **options) ⇒ Object

Parametric aggregates render as name(param)(args); Float/Integer coercion is the injection guard for the parameter.



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 329

def quantile(fraction, column, merge: false, **options)
  aggregate("quantile", [klass.arel_table[column]],
            parameter: Float(fraction), merge: merge, condition: options[:if])
end

#top_k(count, column, merge: false, **options) ⇒ Object 



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 334

def top_k(count, column, merge: false, **options)
  aggregate("topK", [klass.arel_table[column]],
            parameter: Integer(count), merge: merge, condition: options[:if])
end

#uniq_count(column, exact: false, merge: false, **options) ⇒ Object 



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 322

def uniq_count(column, exact: false, merge: false, **options)
  aggregate(exact ? "uniqExact" : "uniq", [klass.arel_table[column]],
            merge: merge, condition: options[:if])
end