Arel VS gsub!

benchmark.rb

require 'benchmark'

def insert_list(table_name:, columns:, values:)
  Arel::InsertManager.new.tap do |manager|
    table = Arel::Table.new(table_name)
    manager.into(table)
    columns.each { |name| manager.columns << table[name] }
    manager.values = manager.create_values_list(values)
  end
end

Benchmark.bm(7) do |x|
  ary = 1.upto(300000).each_slice(3).to_a

  x.report('Arel')   do
    insert_list(
      table_name: 'foos',
      columns: [:a, :b, :c],
      values: ary
    ).to_sql
  end
  x.report("gsub!") do
    query = "insert into table_name (attr1, attr2) VALUES __SQL_VAR__ ;"
   sql_var = ary.uniq.to_s.gsub('[', '(').gsub(']', ')')[1...-1] # removed first and last char to get rid of the outer array brackets
   query.gsub!('__SQL_VAR__', sql_var)
  end
end

results

              user     system      total        real
Arel      1.189341   0.008964   1.198305 (  1.223581)
gsub!     0.621624   0.011881   0.633505 (  0.652518)