Benchmarking raw mapping, pluck, pluck+ map, pluck_all, and pluck_to_hash in rails.
The purpose of this research is knowing which is the best for collecting records. This is still early research, will updated in the future.
I avoid as_json because many benchmarks have stated that as_json is the worst.
To reproduce the benchmark:
console > ActiveRecord::Base.logger.level = 1
console > Benchmarking.new.call
Condition:
- 20 columns for User table
- Ruby 2.6.5
- Rails 6.0.2.1
- Postgresql 9.5
- No limit for DB query
Note:
- The seed CSVs are in
./lib/data/*.csv
Iteration (total records):
- 1_000
- 5_000
- 10_000
- 50_000
- 100_000
- 150_000
1_000 records:
User count: 1000
1st Benchmarking (computation time)...
Rehearsal --------------------------------------------------
map 0.098189 0.000000 0.098189 ( 0.101133)
pluck 0.012563 0.000000 0.012563 ( 0.013810)
pluck + map 0.021662 0.000000 0.021662 ( 0.022901)
pluck_all 0.019378 0.000000 0.019378 ( 0.020921)
pluck_to_hash 0.035684 0.000000 0.035684 ( 0.036995)
----------------------------------------- total: 0.187476sec
user system total real
map 0.045869 0.000000 0.045869 ( 0.047465)
pluck 0.012776 0.000000 0.012776 ( 0.014008)
pluck + map 0.014055 0.000000 0.014055 ( 0.015537)
pluck_all 0.020234 0.000000 0.020234 ( 0.021755)
pluck_to_hash 0.030284 0.000000 0.030284 ( 0.031516)
2nd Benchmarking (iteration per second)...
Warming up --------------------------------------
map 2.000 i/100ms
pluck 7.000 i/100ms
pluck + map 7.000 i/100ms
pluck_all 5.000 i/100ms
pluck_to_hash 3.000 i/100ms
Calculating -------------------------------------
map 23.129 (± 4.3%) i/s - 48.000 in 2.076380s
pluck 83.869 (± 3.6%) i/s - 168.000 in 2.005351s
pluck + map 75.037 (± 2.7%) i/s - 154.000 in 2.053922s
pluck_all 50.902 (± 3.9%) i/s - 105.000 in 2.064878s
pluck_to_hash 32.004 (± 3.1%) i/s - 66.000 in 2.063071s
Comparison:
pluck: 83.9 i/s
pluck + map: 75.0 i/s - 1.12x slower
pluck_all: 50.9 i/s - 1.65x slower
pluck_to_hash : 32.0 i/s - 2.62x slower
map: 23.1 i/s - 3.63x slower
3rd Benchmarking (memory allocation)...
Calculating -------------------------------------
map 6.641M memsize ( 5.469M retained)
65.116k objects ( 63.005k retained)
50.000 strings ( 50.000 retained)
pluck 1.884M memsize ( 888.000 retained)
38.154k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck + map 2.820M memsize ( 888.000 retained)
39.155k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck_all 2.624M memsize ( 928.000 retained)
38.334k objects ( 4.000 retained)
50.000 strings ( 1.000 retained)
pluck_to_hash 10.654M memsize ( 888.000 retained)
107.172k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
Comparison:
pluck: 1884280 allocated
pluck_all: 2624312 allocated - 1.39x more
pluck + map: 2820320 allocated - 1.50x more
map: 6640992 allocated - 3.52x more
pluck_to_hash : 10654136 allocated - 5.65x more
5_000 records:
User count: 5000
1st Benchmarking (computation time)...
Rehearsal --------------------------------------------------
map 0.299461 0.012045 0.311506 ( 0.319321)
pluck 0.052265 0.004389 0.056654 ( 0.060814)
pluck + map 0.068989 0.003736 0.072725 ( 0.076635)
pluck_all 0.103866 0.000020 0.103886 ( 0.107947)
pluck_to_hash 0.225800 0.000184 0.225984 ( 0.230903)
----------------------------------------- total: 0.770755sec
user system total real
map 0.204485 0.004047 0.208532 ( 0.214788)
pluck 0.054522 0.000000 0.054522 ( 0.059755)
pluck + map 0.048983 0.007579 0.056562 ( 0.061417)
pluck_all 0.087587 0.003847 0.091434 ( 0.096618)
pluck_to_hash 0.153479 0.000092 0.153571 ( 0.158700)
2nd Benchmarking (iteration per second)...
Warming up --------------------------------------
map 1.000 i/100ms
pluck 1.000 i/100ms
pluck + map 1.000 i/100ms
pluck_all 1.000 i/100ms
pluck_to_hash 1.000 i/100ms
Calculating -------------------------------------
map 4.619 (± 0.0%) i/s - 10.000 in 2.166926s
pluck 16.517 (± 0.0%) i/s - 34.000 in 2.059771s
pluck + map 14.736 (± 6.8%) i/s - 30.000 in 2.044091s
pluck_all 10.120 (± 0.0%) i/s - 21.000 in 2.076165s
pluck_to_hash 6.586 (±15.2%) i/s - 13.000 in 2.033361s
Comparison:
pluck: 16.5 i/s
pluck + map: 14.7 i/s - 1.12x slower
pluck_all: 10.1 i/s - 1.63x slower
pluck_to_hash : 6.6 i/s - 2.51x slower
map: 4.6 i/s - 3.58x slower
3rd Benchmarking (memory allocation)...
Calculating -------------------------------------
map 33.169M memsize ( 27.341M retained)
325.116k objects ( 315.005k retained)
50.000 strings ( 50.000 retained)
pluck 9.372M memsize ( 888.000 retained)
190.154k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck + map 14.052M memsize ( 888.000 retained)
195.155k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck_all 13.040M memsize ( 928.000 retained)
190.334k objects ( 4.000 retained)
50.000 strings ( 1.000 retained)
pluck_to_hash 53.214M memsize ( 888.000 retained)
535.172k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
Comparison:
pluck: 9372280 allocated
pluck_all: 13040288 allocated - 1.39x more
pluck + map: 14052320 allocated - 1.50x more
map: 33168944 allocated - 3.54x more
pluck_to_hash : 53214136 allocated - 5.68x more
10_000 records:
User count: 10000
1st Benchmarking (computation time)...
Rehearsal --------------------------------------------------
map 0.513401 0.013371 0.526772 ( 0.540751)
pluck 0.209123 0.015730 0.224853 ( 0.232538)
pluck + map 0.149200 0.004133 0.153333 ( 0.164048)
pluck_all 0.172368 0.000385 0.172753 ( 0.183457)
pluck_to_hash 0.298585 0.000461 0.299046 ( 0.307496)
----------------------------------------- total: 1.376757sec
user system total real
map 0.394183 0.012348 0.406531 ( 0.418312)
pluck 0.101573 0.000000 0.101573 ( 0.113351)
pluck + map 0.105160 0.000000 0.105160 ( 0.116371)
pluck_all 0.176093 0.003510 0.179603 ( 0.191376)
pluck_to_hash 0.316427 0.000000 0.316427 ( 0.327497)
2nd Benchmarking (iteration per second)...
Warming up --------------------------------------
map 1.000 i/100ms
pluck 1.000 i/100ms
pluck + map 1.000 i/100ms
pluck_all 1.000 i/100ms
pluck_to_hash 1.000 i/100ms
Calculating -------------------------------------
map 2.140 (± 0.0%) i/s - 5.000 in 2.339074s
pluck 8.738 (± 0.0%) i/s - 18.000 in 2.063371s
pluck + map 8.124 (± 0.0%) i/s - 17.000 in 2.094784s
pluck_all 5.338 (± 0.0%) i/s - 11.000 in 2.062006s
pluck_to_hash 2.975 (± 0.0%) i/s - 7.000 in 2.379071s
Comparison:
pluck: 8.7 i/s
pluck + map: 8.1 i/s - 1.08x slower
pluck_all: 5.3 i/s - 1.64x slower
pluck_to_hash : 3.0 i/s - 2.94x slower
map: 2.1 i/s - 4.08x slower
3rd Benchmarking (memory allocation)...
Calculating -------------------------------------
map 66.269M memsize ( 54.651M retained)
650.116k objects ( 630.005k retained)
50.000 strings ( 50.000 retained)
pluck 18.732M memsize ( 888.000 retained)
380.154k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck + map 28.092M memsize ( 888.000 retained)
390.155k objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck_all 26.030M memsize ( 928.000 retained)
380.334k objects ( 4.000 retained)
50.000 strings ( 1.000 retained)
pluck_to_hash 106.414M memsize ( 888.000 retained)
1.070M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
Comparison:
pluck: 18732280 allocated
pluck_all: 26030184 allocated - 1.39x more
pluck + map: 28092320 allocated - 1.50x more
map: 66268736 allocated - 3.54x more
pluck_to_hash : 106414136 allocated - 5.68x more
50_000 records:
User count: 50000
1st Benchmarking (computation time)...
Rehearsal --------------------------------------------------
map 3.498618 0.072091 3.570709 ( 3.617245)
pluck 0.456679 0.032203 0.488882 ( 0.532634)
pluck + map 0.683851 0.027709 0.711560 ( 0.750596)
pluck_all 1.198362 0.020189 1.218551 ( 1.258880)
pluck_to_hash 1.603715 0.004141 1.607856 ( 1.653269)
----------------------------------------- total: 7.597558sec
user system total real
map 3.021492 0.000000 3.021492 ( 3.075048)
pluck 0.461127 0.003648 0.464775 ( 0.517436)
pluck + map 0.640119 0.007924 0.648043 ( 0.699815)
pluck_all 0.925029 0.008374 0.933403 ( 0.993112)
pluck_to_hash 1.860904 0.007895 1.868799 ( 1.919054)
2nd Benchmarking (iteration per second)...
Warming up --------------------------------------
map 1.000 i/100ms
pluck 1.000 i/100ms
pluck + map 1.000 i/100ms
pluck_all 1.000 i/100ms
pluck_to_hash 1.000 i/100ms
Calculating -------------------------------------
map 0.358 (± 0.0%) i/s - 1.000 in 2.796498s
pluck 1.859 (± 0.0%) i/s - 4.000 in 2.159543s
pluck + map 1.321 (± 0.0%) i/s - 3.000 in 2.287014s
pluck_all 0.956 (± 0.0%) i/s - 2.000 in 2.137202s
pluck_to_hash 0.588 (± 0.0%) i/s - 2.000 in 3.408785s
Comparison:
pluck: 1.9 i/s
pluck + map: 1.3 i/s - 1.41x slower
pluck_all: 1.0 i/s - 1.95x slower
pluck_to_hash : 0.6 i/s - 3.16x slower
map: 0.4 i/s - 5.20x slower
3rd Benchmarking (memory allocation)...
Calculating -------------------------------------
map 331.317M memsize ( 273.710M retained)
3.250M objects ( 3.150M retained)
50.000 strings ( 50.000 retained)
pluck 93.612M memsize ( 888.000 retained)
1.900M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck + map 140.412M memsize ( 888.000 retained)
1.950M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck_all 130.075M memsize ( 928.000 retained)
1.900M objects ( 4.000 retained)
50.000 strings ( 1.000 retained)
pluck_to_hash 532.014M memsize ( 888.000 retained)
5.350M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
Comparison:
pluck: 93612280 allocated
pluck_all: 130074528 allocated - 1.39x more
pluck + map: 140412320 allocated - 1.50x more
map: 331317424 allocated - 3.54x more
pluck_to_hash : 532014136 allocated - 5.68x more
100_000 records:
User count: 100000
1st Benchmarking (computation time)...
Rehearsal --------------------------------------------------
map 8.072061 0.231988 8.304049 ( 8.414657)
pluck 1.528179 0.031877 1.560056 ( 1.663788)
pluck + map 1.960579 0.024053 1.984632 ( 2.114030)
pluck_all 2.015920 0.008485 2.024405 ( 2.117514)
pluck_to_hash 3.702269 0.011736 3.714005 ( 3.809000)
---------------------------------------- total: 17.587147sec
user system total real
map 6.022514 0.016143 6.038657 ( 6.130699)
pluck 1.111072 0.000388 1.111460 ( 1.211779)
pluck + map 1.521913 0.008054 1.529967 ( 1.635111)
pluck_all 2.235455 0.016092 2.251547 ( 2.378318)
pluck_to_hash 3.157268 0.016195 3.173463 ( 3.271163)
2nd Benchmarking (iteration per second)...
Warming up --------------------------------------
map 1.000 i/100ms
pluck 1.000 i/100ms
pluck + map 1.000 i/100ms
pluck_all 1.000 i/100ms
pluck_to_hash 1.000 i/100ms
Calculating -------------------------------------
map 0.133 (± 0.0%) i/s - 1.000 in 7.500780s
pluck 0.795 (± 0.0%) i/s - 2.000 in 2.541874s
pluck + map 0.602 (± 0.0%) i/s - 2.000 in 3.325233s
pluck_all 0.394 (± 0.0%) i/s - 1.000 in 2.539895s
pluck_to_hash 0.283 (± 0.0%) i/s - 1.000 in 3.531340s
Comparison:
pluck: 0.8 i/s
pluck + map: 0.6 i/s - 1.32x slower
pluck_all: 0.4 i/s - 2.02x slower
pluck_to_hash : 0.3 i/s - 2.81x slower
map: 0.1 i/s - 5.97x slower
3rd Benchmarking (memory allocation)...
Calculating -------------------------------------
map 662.852M memsize ( 546.623M retained)
6.500M objects ( 6.300M retained)
50.000 strings ( 50.000 retained)
pluck 187.212M memsize ( 888.000 retained)
3.800M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck + map 280.812M memsize ( 888.000 retained)
3.900M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck_all 260.242M memsize ( 928.000 retained)
3.800M objects ( 4.000 retained)
50.000 strings ( 1.000 retained)
pluck_to_hash 1.064B memsize ( 888.000 retained)
10.700M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
Comparison:
pluck: 187212280 allocated
pluck_all: 260242064 allocated - 1.39x more
pluck + map: 280812320 allocated - 1.50x more
map: 662852496 allocated - 3.54x more
pluck_to_hash : 1064015064 allocated - 5.68x more
150_000 records:
User count: 150000
1st Benchmarking (computation time)...
Rehearsal --------------------------------------------------
map 12.840149 0.395742 13.235891 ( 13.405972)
pluck 1.716401 0.108963 1.825364 ( 1.963149)
pluck + map 3.282409 0.052076 3.334485 ( 3.461505)
pluck_all 3.538375 0.035789 3.574164 ( 3.719665)
pluck_to_hash 5.467220 0.012392 5.479612 ( 5.617068)
---------------------------------------- total: 27.449516sec
user system total real
map 10.179698 0.047143 10.226841 ( 10.369526)
pluck 1.810056 0.019949 1.830005 ( 1.976608)
pluck + map 2.511327 0.016246 2.527573 ( 2.674145)
pluck_all 3.351025 0.031985 3.383010 ( 3.532227)
pluck_to_hash 5.163056 0.024184 5.187240 ( 5.332552)
2nd Benchmarking (iteration per second)...
Warming up --------------------------------------
map 1.000 i/100ms
pluck 1.000 i/100ms
pluck + map 1.000 i/100ms
pluck_all 1.000 i/100ms
pluck_to_hash 1.000 i/100ms
Calculating -------------------------------------
map 0.096 (± 0.0%) i/s - 1.000 in 10.440622s
pluck 0.559 (± 0.0%) i/s - 2.000 in 3.609355s
pluck + map 0.413 (± 0.0%) i/s - 1.000 in 2.420296s
pluck_all 0.285 (± 0.0%) i/s - 1.000 in 3.505057s
pluck_to_hash 0.187 (± 0.0%) i/s - 1.000 in 5.356537s
Comparison:
pluck: 0.6 i/s
pluck + map: 0.4 i/s - 1.35x slower
pluck_all: 0.3 i/s - 1.96x slower
pluck_to_hash : 0.2 i/s - 2.99x slower
map: 0.1 i/s - 5.83x slower
3rd Benchmarking (memory allocation)...
Calculating -------------------------------------
map 994.275M memsize ( 819.933M retained)
9.750M objects ( 9.450M retained)
50.000 strings ( 50.000 retained)
pluck 280.812M memsize ( 888.000 retained)
5.700M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck + map 421.212M memsize ( 888.000 retained)
5.850M objects ( 3.000 retained)
50.000 strings ( 1.000 retained)
pluck_all 390.353M memsize ( 928.000 retained)
5.700M objects ( 4.000 retained)
50.000 strings ( 1.000 retained)
pluck_to_hash 1.596B memsize ( 1.816k retained)
16.050M objects ( 11.000 retained)
50.000 strings ( 2.000 retained)
Comparison:
pluck: 280812280 allocated
pluck_all: 390352848 allocated - 1.39x more
pluck + map: 421212320 allocated - 1.50x more
map: 994274992 allocated - 3.54x more
pluck_to_hash : 1596015064 allocated - 5.68x more
Conclusion:
- While pluck is the most powerful, it only resulting in array of array, not array of hash like we intended;
pluck + maphas higher performance thanpluck_all, but the earlier need to be configured as you can see in theis_pluck_mapmethod;- Use
pluck_allrather thanpluck_to_hashif we want to use gem.