benchmark.jl

using BenchmarkTools

struct VarRef
    x::UInt64
end
function f(A, B)
    s = 0
    for y in Y
        s += X[y]
    end
    s
end

m = 100_000_000
n = 100_000

X = rand(Int, n);
Y = mod.(rand(Int, m), n) .+ 1;
Z = VarRef.(Y);
U = Dict{VarRef, Int}();
for i in 1:length(X)
    U[VarRef(i)] = X[i]
end
println("Array Access")
display(@benchmark f($X, $Y))
println("\nDict Access")
display(@benchmark f($U, $Z))

output

C:\Users\odow003\.julia\v0.6\CPLEX\src\MOI>D:/Julia/Julia-0.6/bin/Julia.exe benchmark.jl
Array Access
BenchmarkTools.Trial:
  memory estimate:  8.93 GiB
  allocs estimate:  499488209
  --------------
  minimum time:     14.547 s (2.61% GC)
  median time:      14.547 s (2.61% GC)
  mean time:        14.547 s (2.61% GC)
  maximum time:     14.547 s (2.61% GC)
  --------------
  samples:          1
  evals/sample:     1
Dict Access
BenchmarkTools.Trial:
  memory estimate:  8.93 GiB
  allocs estimate:  499488209
  --------------
  minimum time:     14.247 s (2.78% GC)
  median time:      14.247 s (2.78% GC)
  mean time:        14.247 s (2.78% GC)
  maximum time:     14.247 s (2.78% GC)
  --------------
  samples:          1
  evals/sample:     1