Benchmark is a module provided by ruby which helps you to measure the time taken to execute

a particular method or line in ruby code

benchmark reports the time taken to execute the ruby code

How to install:-

gem ‘benchmark’

and then bundle or install it as

gem install benchmark

How to use:-

suppose you’re doing a ton of queries and you need to figure out what is faster in retrieving the record which or find for that purpose, you can benchmark it.

let’s consider you have one method which uses find

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def meth
  a = User.find(1)
end

and another method which uses where

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def meth2
  a = User.where(id: 1)
end

syntax to benchmark a method is:-

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Benchmark.bm do |x|
 x.report { method_name }
end

the result will look like

result for meth(find)

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Benchmark.bm do |x|
 x.report { meth }
end
       user     system      total        real
  0.050131   0.009857   0.059988 (  0.121509)

and result for meth2(where)

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Benchmark.bm do |x|
 x.report { meth2 }
end
       user     system      total        real
   0.000335   0.000457   0.000792 (  0.000963)

and suppose you have to benchmark a single line of code

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puts Benchmark.measure { [1,2,3,4,5].map{|digit| [digit, digit]}.to_h }
    user     system      total        real
0.000007   0.000005   0.000012 (  0.000005)

With help of this, we can figure out which method is faster

as you can see the output which comes after the benchmark is in different rows

user: the amount of time spent executing userspace code(code which we are running) system: the amount of time spent on executing operating system’s function

total: user + real

real: system + user + time spent waiting for I/O, network, disk, user input, etc also known as wallclock time