gistfile1.rb

10.times do
  r = Restaurant.find(:all, :conditions => ['id IN (?)', ids])
  r.map(&:cuisines).flatten.map(&:id)
end

# benchmarked 10 times
     user     system      total        real
10.170000   0.470000  10.640000 ( 11.809886)
 9.630000   0.410000  10.040000 ( 11.076710)
11.220000   0.520000  11.740000 ( 12.819519)
11.140000   0.530000  11.670000 ( 12.702499)
10.040000   0.520000  10.560000 ( 11.654553)
10.680000   0.470000  11.150000 ( 12.250775)
10.050000   0.700000  10.750000 ( 11.763682)
11.020000   0.480000  11.500000 ( 12.893516)
10.410000   0.590000  11.000000 ( 12.181406)
11.460000   0.740000  12.200000 ( 13.326383)

# memory diff from baseline IRB for each run [1]
8712, 15000, 15092, 15204, 15260, 15324, 15360, 15392, 15424, 15428