The process dictionary is globally accessible with trickery (erlang:process_info/1) and is not used in testable source code, so the process dictionary is considered to be as bad as global state. The reason the process dictionary is bad is because its scope is undefined, since it is attached to the lifetime of the Erlang process (not to mention that it complicates the fault-tolerance of any stored data). The process dictionary is a single dictionary shared with all source code the Erlang process executes, so external source code can make its contents undefined also!
ETS is a more typical way to store global state as key/value pairs. With concurrency (operations that are not atomic) global state depends on locking to maintain consistency and it is the data locking that limits scalability. Erlang's main strength is its avoidance of global data locks, so it is only natural to pursue data structures that avoid global data.
(from string_key test below) N == 64000 (10 runs) aadict get: 233343.8 µs ( 5.4), set: 440130.2 µs ( 2.6) dict get: 137424.3 µs ( 3.2), set: 871894.4 µs ( 5.2) ets (ordered_set) get: 177797.4 µs ( 4.1), set: 211416.5 µs ( 1.3) ets (set) get: 114235.0 µs ( 2.6), set: 169276.2 µs ( 1.0) ets x10 read (ordere get: 169068.3 µs ( 3.9) ets x10 read (set) get: 134240.8 µs ( 3.1) gb_trees get: 255160.6 µs ( 5.9), set: 488567.1 µs ( 2.9) hashtl get: 129433.1 µs ( 3.0), set: 210779.3 µs ( 1.3) process dictionary get: 77023.9 µs ( 1.8), set: 166122.5 µs ( 1.0) rbdict get: 230949.9 µs ( 5.3), set: 372831.9 µs ( 2.2) trie get: 43435.1 µs ( 1.0), set: 379677.6 µs ( 2.3)
Just looking at string lookup results for a relatively large number of strings (64000) to hold in RAM shows that the trie string "get" is the fastest and the hashtl "set" is tied for second fastest (with both ETS and the process dictionary being the fastest alternative). You could also say that for accessing 64000 common strings, the trie and the hashtl source code are currently the fastest local string associative data storage in Erlang, if you accept that the scope of the process dictionary is non-local.
The ETS test shows the extra latency that occurs with a string "get" operation on both set and ordered_set with read_concurrency set to true. The latency changes by a factor of 0.951 for the ordered_set and a factor of 1.175 for the set when the number of processes doing concurrent read operations increases from 1 to 10. So the scalability benefit of using the trie (ignoring its efficiency) rather than ETS is obvious for the set but the ordered_set requires testing with more concurrent reads to show scalability benefits.
The benchmark results are from Linux version 2.6.32-21, Ubuntu 10.04 with an Intel(R) Core(TM)2 CPU T5600 @ 1.83GHz and non-HiPE Erlang R14B02:
TEST string_key N == 50 (10 runs) aadict get: 18.5 µs ( 1.1), set: 61.5 µs ( 1.2) dict get: 32.1 µs ( 1.9), set: 119.4 µs ( 2.4) ets (ordered_set) get: 30.6 µs ( 1.8), set: 50.0 µs ( 1.0) ets (set) get: 31.1 µs ( 1.8), set: 53.9 µs ( 1.1) ets x10 read (ordere get: 39.8 µs ( 2.4) ets x10 read (set) get: 41.5 µs ( 2.5) gb_trees get: 22.9 µs ( 1.4), set: 92.3 µs ( 1.8) hashtl get: 27.4 µs ( 1.6), set: 58.7 µs ( 1.2) process dictionary get: 19.5 µs ( 1.2), set: 74.1 µs ( 1.5) rbdict get: 18.2 µs ( 1.1), set: 52.6 µs ( 1.1) trie get: 16.9 µs ( 1.0), set: 108.0 µs ( 2.2) N == 100 (10 runs) aadict get: 43.4 µs ( 1.3), set: 147.1 µs ( 1.5) dict get: 68.8 µs ( 2.0), set: 251.4 µs ( 2.5) ets (ordered_set) get: 65.4 µs ( 1.9), set: 99.6 µs ( 1.0) ets (set) get: 59.2 µs ( 1.7), set: 100.8 µs ( 1.0) ets x10 read (ordere get: 99.6 µs ( 2.9) ets x10 read (set) get: 77.7 µs ( 2.3) gb_trees get: 51.3 µs ( 1.5), set: 200.4 µs ( 2.0) hashtl get: 54.5 µs ( 1.6), set: 116.7 µs ( 1.2) process dictionary get: 38.5 µs ( 1.1), set: 224.8 µs ( 2.3) rbdict get: 43.4 µs ( 1.3), set: 111.2 µs ( 1.1) trie get: 33.9 µs ( 1.0), set: 210.2 µs ( 2.1) N == 250 (10 runs) aadict get: 135.5 µs ( 1.5), set: 430.9 µs ( 1.9) dict get: 178.5 µs ( 1.9), set: 709.3 µs ( 3.1) ets (ordered_set) get: 167.5 µs ( 1.8), set: 311.4 µs ( 1.4) ets (set) get: 148.8 µs ( 1.6), set: 250.1 µs ( 1.1) ets x10 read (ordere get: 266.5 µs ( 2.9) ets x10 read (set) get: 270.7 µs ( 2.9) gb_trees get: 155.3 µs ( 1.7), set: 685.9 µs ( 3.0) hashtl get: 161.6 µs ( 1.7), set: 229.0 µs ( 1.0) process dictionary get: 92.6 µs ( 1.0), set: 296.4 µs ( 1.3) rbdict get: 143.2 µs ( 1.5), set: 334.2 µs ( 1.5) trie get: 95.3 µs ( 1.0), set: 507.2 µs ( 2.2) N == 500 (10 runs) aadict get: 332.5 µs ( 1.7), set: 1090.7 µs ( 1.9) dict get: 364.6 µs ( 1.9), set: 1440.2 µs ( 2.5) ets (ordered_set) get: 410.8 µs ( 2.1), set: 1466.0 µs ( 2.5) ets (set) get: 302.6 µs ( 1.6), set: 586.5 µs ( 1.0) ets x10 read (ordere get: 573.1 µs ( 3.0) ets x10 read (set) get: 494.3 µs ( 2.6) gb_trees get: 365.2 µs ( 1.9), set: 1334.5 µs ( 2.3) hashtl get: 388.7 µs ( 2.0), set: 800.4 µs ( 1.4) process dictionary get: 191.6 µs ( 1.0), set: 718.8 µs ( 1.2) rbdict get: 330.7 µs ( 1.7), set: 755.5 µs ( 1.3) trie get: 220.4 µs ( 1.2), set: 981.8 µs ( 1.7) N == 1000 (10 runs) aadict get: 798.7 µs ( 1.1), set: 2322.7 µs ( 1.5) dict get: 1093.8 µs ( 1.5), set: 3336.9 µs ( 2.1) ets (ordered_set) get: 1163.9 µs ( 1.6), set: 2343.4 µs ( 1.5) ets (set) get: 976.2 µs ( 1.4), set: 1561.4 µs ( 1.0) ets x10 read (ordere get: 1071.3 µs ( 1.5) ets x10 read (set) get: 1118.5 µs ( 1.6) gb_trees get: 927.4 µs ( 1.3), set: 3017.3 µs ( 1.9) hashtl get: 1346.6 µs ( 1.9), set: 1754.8 µs ( 1.1) process dictionary get: 747.5 µs ( 1.1), set: 1771.5 µs ( 1.1) rbdict get: 786.5 µs ( 1.1), set: 1806.9 µs ( 1.2) trie get: 709.1 µs ( 1.0), set: 2468.1 µs ( 1.6) N == 2000 (10 runs) aadict get: 2196.6 µs ( 1.2), set: 5800.6 µs ( 1.6) dict get: 2980.3 µs ( 1.6), set: 7976.8 µs ( 2.2) ets (ordered_set) get: 3098.8 µs ( 1.6), set: 4165.5 µs ( 1.1) ets (set) get: 2966.1 µs ( 1.6), set: 4373.5 µs ( 1.2) ets x10 read (ordere get: 2640.6 µs ( 1.4) ets x10 read (set) get: 2850.6 µs ( 1.5) gb_trees get: 2320.3 µs ( 1.2), set: 6872.1 µs ( 1.9) hashtl get: 3581.9 µs ( 1.9), set: 3662.4 µs ( 1.0) process dictionary get: 2389.5 µs ( 1.3), set: 4164.2 µs ( 1.1) rbdict get: 2076.3 µs ( 1.1), set: 4576.0 µs ( 1.2) trie get: 1907.3 µs ( 1.0), set: 5780.9 µs ( 1.6) N == 4000 (10 runs) aadict get: 5877.5 µs ( 1.3), set: 13809.0 µs ( 1.7) dict get: 6491.3 µs ( 1.5), set: 18633.8 µs ( 2.4) ets (ordered_set) get: 7127.5 µs ( 1.6), set: 9145.6 µs ( 1.2) ets (set) get: 6153.2 µs ( 1.4), set: 7919.1 µs ( 1.0) ets x10 read (ordere get: 8061.6 µs ( 1.8) ets x10 read (set) get: 7786.1 µs ( 1.8) gb_trees get: 6424.2 µs ( 1.5), set: 15693.2 µs ( 2.0) hashtl get: 7054.5 µs ( 1.6), set: 8605.5 µs ( 1.1) process dictionary get: 4938.2 µs ( 1.1), set: 9578.4 µs ( 1.2) rbdict get: 5788.3 µs ( 1.3), set: 11456.6 µs ( 1.4) trie get: 4376.9 µs ( 1.0), set: 13757.2 µs ( 1.7) N == 8000 (10 runs) aadict get: 15730.6 µs ( 1.8), set: 34177.0 µs ( 2.1) dict get: 14520.8 µs ( 1.6), set: 44817.0 µs ( 2.7) ets (ordered_set) get: 16009.9 µs ( 1.8), set: 19875.4 µs ( 1.2) ets (set) get: 13122.3 µs ( 1.5), set: 16436.0 µs ( 1.0) ets x10 read (ordere get: 19029.0 µs ( 2.1) ets x10 read (set) get: 16993.7 µs ( 1.9) gb_trees get: 17208.8 µs ( 1.9), set: 36673.0 µs ( 2.2) hashtl get: 15175.1 µs ( 1.7), set: 16599.3 µs ( 1.0) process dictionary get: 10157.7 µs ( 1.1), set: 21110.6 µs ( 1.3) rbdict get: 15758.7 µs ( 1.8), set: 28566.6 µs ( 1.7) trie get: 8940.0 µs ( 1.0), set: 28293.8 µs ( 1.7) N == 16000 (10 runs) aadict get: 41375.3 µs ( 2.0), set: 82925.0 µs ( 2.2) dict get: 29842.0 µs ( 1.4), set: 108119.5 µs ( 2.9) ets (ordered_set) get: 36909.9 µs ( 1.8), set: 43162.0 µs ( 1.2) ets (set) get: 28240.8 µs ( 1.4), set: 37495.3 µs ( 1.0) ets x10 read (ordere get: 40634.9 µs ( 2.0) ets x10 read (set) get: 35608.5 µs ( 1.7) gb_trees get: 44022.7 µs ( 2.1), set: 93643.0 µs ( 2.5) hashtl get: 37419.0 µs ( 1.8), set: 48790.5 µs ( 1.3) process dictionary get: 20684.6 µs ( 1.0), set: 43798.3 µs ( 1.2) rbdict get: 40916.6 µs ( 2.0), set: 71371.2 µs ( 1.9) trie get: 21225.2 µs ( 1.0), set: 69109.4 µs ( 1.8) N == 32000 (10 runs) aadict get: 97193.5 µs ( 2.3), set: 188024.4 µs ( 2.3) dict get: 64191.5 µs ( 1.5), set: 300668.6 µs ( 3.6) ets (ordered_set) get: 83813.1 µs ( 2.0), set: 100045.7 µs ( 1.2) ets (set) get: 60364.4 µs ( 1.4), set: 83030.4 µs ( 1.0) ets x10 read (ordere get: 86087.9 µs ( 2.0) ets x10 read (set) get: 74093.9 µs ( 1.8) gb_trees get: 107121.1 µs ( 2.5), set: 214457.9 µs ( 2.6) hashtl get: 68200.3 µs ( 1.6), set: 112145.8 µs ( 1.4) process dictionary get: 42152.3 µs ( 1.0), set: 93514.7 µs ( 1.1) rbdict get: 96665.2 µs ( 2.3), set: 160379.7 µs ( 1.9) trie get: 54760.0 µs ( 1.3), set: 213854.1 µs ( 2.6) N == 64000 (10 runs) aadict get: 233343.8 µs ( 5.4), set: 440130.2 µs ( 2.6) dict get: 137424.3 µs ( 3.2), set: 871894.4 µs ( 5.2) ets (ordered_set) get: 177797.4 µs ( 4.1), set: 211416.5 µs ( 1.3) ets (set) get: 114235.0 µs ( 2.6), set: 169276.2 µs ( 1.0) ets x10 read (ordere get: 169068.3 µs ( 3.9) ets x10 read (set) get: 134240.8 µs ( 3.1) gb_trees get: 255160.6 µs ( 5.9), set: 488567.1 µs ( 2.9) hashtl get: 129433.1 µs ( 3.0), set: 210779.3 µs ( 1.3) process dictionary get: 77023.9 µs ( 1.8), set: 166122.5 µs ( 1.0) rbdict get: 230949.9 µs ( 5.3), set: 372831.9 µs ( 2.2) trie get: 43435.1 µs ( 1.0), set: 379677.6 µs ( 2.3) TEST integer_key N == 50 (10 runs) aadict get: 16.2 µs ( 3.2), set: 54.9 µs ( 5.8) array (dynamic) get: 15.0 µs ( 2.9), set: 25.5 µs ( 2.7) array (fixed) get: 15.3 µs ( 3.0), set: 26.5 µs ( 2.8) dict get: 22.2 µs ( 4.4), set: 51.0 µs ( 5.4) ets (ordered_set) get: 21.9 µs ( 4.3), set: 29.1 µs ( 3.1) ets (set) get: 16.3 µs ( 3.2), set: 25.8 µs ( 2.7) ets x10 read (ordere get: 20.2 µs ( 4.0) ets x10 read (set) get: 16.8 µs ( 3.3) gb_trees get: 17.3 µs ( 3.4), set: 104.8 µs ( 11.1) hashtl get: 16.6 µs ( 3.3), set: 38.6 µs ( 4.1) process dictionary get: 8.2 µs ( 1.6), set: 9.4 µs ( 1.0) rbdict get: 15.8 µs ( 3.1), set: 43.8 µs ( 4.7) tuple get: 5.1 µs ( 1.0), set: 13.0 µs ( 1.4) N == 100 (10 runs) aadict get: 43.0 µs ( 4.3), set: 128.1 µs ( 7.9) array (dynamic) get: 28.4 µs ( 2.9), set: 51.0 µs ( 3.1) array (fixed) get: 28.6 µs ( 2.9), set: 50.9 µs ( 3.1) dict get: 48.6 µs ( 4.9), set: 121.6 µs ( 7.5) ets (ordered_set) get: 42.4 µs ( 4.3), set: 57.7 µs ( 3.6) ets (set) get: 98.6 µs ( 10.0), set: 56.5 µs ( 3.5) ets x10 read (ordere get: 37.7 µs ( 3.8) ets x10 read (set) get: 26.9 µs ( 2.7) gb_trees get: 36.3 µs ( 3.7), set: 263.0 µs ( 16.2) hashtl get: 35.3 µs ( 3.6), set: 76.6 µs ( 4.7) process dictionary get: 15.1 µs ( 1.5), set: 16.2 µs ( 1.0) rbdict get: 34.5 µs ( 3.5), set: 106.2 µs ( 6.6) tuple get: 9.9 µs ( 1.0), set: 47.9 µs ( 3.0) N == 250 (10 runs) aadict get: 103.4 µs ( 5.2), set: 430.5 µs ( 8.9) array (dynamic) get: 99.0 µs ( 5.0), set: 187.0 µs ( 3.9) array (fixed) get: 96.7 µs ( 4.9), set: 195.8 µs ( 4.1) dict get: 113.4 µs ( 5.7), set: 868.7 µs ( 18.0) ets (ordered_set) get: 101.7 µs ( 5.1), set: 150.4 µs ( 3.1) ets (set) get: 87.5 µs ( 4.4), set: 149.0 µs ( 3.1) ets x10 read (ordere get: 85.0 µs ( 4.3) ets x10 read (set) get: 64.6 µs ( 3.2) gb_trees get: 102.2 µs ( 5.1), set: 883.4 µs ( 18.3) hashtl get: 131.7 µs ( 6.6), set: 177.9 µs ( 3.7) process dictionary get: 36.0 µs ( 1.8), set: 48.3 µs ( 1.0) rbdict get: 97.0 µs ( 4.9), set: 346.5 µs ( 7.2) tuple get: 19.9 µs ( 1.0), set: 331.4 µs ( 6.9) N == 500 (10 runs) aadict get: 215.0 µs ( 5.1), set: 1129.6 µs ( 12.6) array (dynamic) get: 194.3 µs ( 4.6), set: 444.6 µs ( 5.0) array (fixed) get: 198.1 µs ( 4.7), set: 456.6 µs ( 5.1) dict get: 221.7 µs ( 5.2), set: 1258.3 µs ( 14.0) ets (ordered_set) get: 220.4 µs ( 5.2), set: 308.5 µs ( 3.4) ets (set) get: 158.3 µs ( 3.7), set: 273.8 µs ( 3.1) ets x10 read (ordere get: 172.4 µs ( 4.1) ets x10 read (set) get: 113.1 µs ( 2.7) gb_trees get: 223.1 µs ( 5.3), set: 2430.2 µs ( 27.1) hashtl get: 266.2 µs ( 6.3), set: 500.3 µs ( 5.6) process dictionary get: 66.2 µs ( 1.6), set: 89.7 µs ( 1.0) rbdict get: 214.4 µs ( 5.1), set: 985.1 µs ( 11.0) tuple get: 42.4 µs ( 1.0), set: 2230.6 µs ( 24.9) N == 1000 (10 runs) aadict get: 472.9 µs ( 5.7), set: 1953.9 µs ( 12.8) array (dynamic) get: 429.1 µs ( 5.1), set: 759.1 µs ( 5.0) array (fixed) get: 424.9 µs ( 5.1), set: 1118.4 µs ( 7.3) dict get: 436.0 µs ( 5.2), set: 2460.1 µs ( 16.1) ets (ordered_set) get: 436.5 µs ( 5.2), set: 870.3 µs ( 5.7) ets (set) get: 330.5 µs ( 4.0), set: 522.7 µs ( 3.4) ets x10 read (ordere get: 335.9 µs ( 4.0) ets x10 read (set) get: 207.3 µs ( 2.5) gb_trees get: 494.3 µs ( 5.9), set: 4548.2 µs ( 29.7) hashtl get: 485.6 µs ( 5.8), set: 1291.5 µs ( 8.4) process dictionary get: 129.7 µs ( 1.6), set: 153.0 µs ( 1.0) rbdict get: 474.4 µs ( 5.7), set: 1635.0 µs ( 10.7) tuple get: 83.6 µs ( 1.0), set: 5586.7 µs ( 36.5) N == 2000 (10 runs) aadict get: 1083.5 µs ( 6.8), set: 5727.8 µs ( 9.5) array (dynamic) get: 1113.2 µs ( 7.0), set: 2274.1 µs ( 3.8) array (fixed) get: 985.6 µs ( 6.2), set: 2235.5 µs ( 3.7) dict get: 904.9 µs ( 5.7), set: 6388.5 µs ( 10.6) ets (ordered_set) get: 907.6 µs ( 5.7), set: 1283.6 µs ( 2.1) ets (set) get: 702.4 µs ( 4.4), set: 1124.5 µs ( 1.9) ets x10 read (ordere get: 614.8 µs ( 3.9) ets x10 read (set) get: 384.6 µs ( 2.4) gb_trees get: 1109.6 µs ( 7.0), set: 12070.2 µs ( 20.0) hashtl get: 1083.8 µs ( 6.8), set: 2065.2 µs ( 3.4) process dictionary get: 258.2 µs ( 1.6), set: 603.9 µs ( 1.0) rbdict get: 1080.8 µs ( 6.8), set: 4763.0 µs ( 7.9) tuple get: 159.3 µs ( 1.0), set: 39640.4 µs ( 65.6) N == 4000 (10 runs) aadict get: 2634.7 µs ( 8.3), set: 10477.9 µs ( 15.9) array (dynamic) get: 1987.0 µs ( 6.3), set: 3746.9 µs ( 5.7) array (fixed) get: 2069.9 µs ( 6.5), set: 4359.8 µs ( 6.6) dict get: 2059.9 µs ( 6.5), set: 9022.6 µs ( 13.7) ets (ordered_set) get: 1874.6 µs ( 5.9), set: 2586.1 µs ( 3.9) ets (set) get: 1433.8 µs ( 4.5), set: 2526.4 µs ( 3.8) ets x10 read (ordere get: 1222.8 µs ( 3.9) ets x10 read (set) get: 761.1 µs ( 2.4) gb_trees get: 2287.2 µs ( 7.2), set: 27537.3 µs ( 41.7) hashtl get: 2361.7 µs ( 7.5), set: 3410.8 µs ( 5.2) process dictionary get: 510.0 µs ( 1.6), set: 660.0 µs ( 1.0) rbdict get: 2750.5 µs ( 8.7), set: 9114.6 µs ( 13.8) tuple get: 316.2 µs ( 1.0), set: 151840.8 µs (230.1) N == 8000 (10 runs) aadict get: 5749.0 µs ( 9.3), set: 20115.9 µs ( 16.5) array (dynamic) get: 3995.8 µs ( 6.4), set: 9530.1 µs ( 7.8) array (fixed) get: 4147.7 µs ( 6.7), set: 9336.6 µs ( 7.6) dict get: 4393.0 µs ( 7.1), set: 20980.3 µs ( 17.2) ets (ordered_set) get: 3966.9 µs ( 6.4), set: 5457.4 µs ( 4.5) ets (set) get: 2890.5 µs ( 4.7), set: 5415.8 µs ( 4.4) ets x10 read (ordere get: 2441.7 µs ( 3.9) ets x10 read (set) get: 1529.0 µs ( 2.5) gb_trees get: 5126.7 µs ( 8.3), set: 57499.8 µs ( 47.0) hashtl get: 5180.1 µs ( 8.4), set: 8602.0 µs ( 7.0) process dictionary get: 1035.3 µs ( 1.7), set: 1222.7 µs ( 1.0) rbdict get: 5657.5 µs ( 9.1), set: 17929.1 µs ( 14.7) tuple get: 619.7 µs ( 1.0), set: 617050.7 µs (504.7) N == 16000 (10 runs) aadict get: 11571.6 µs ( 9.5), set: 45005.3 µs ( 15.6) array (dynamic) get: 9951.0 µs ( 8.2), set: 24316.3 µs ( 8.4) array (fixed) get: 9905.7 µs ( 8.1), set: 23415.4 µs ( 8.1) dict get: 8804.0 µs ( 7.2), set: 67758.2 µs ( 23.4) ets (ordered_set) get: 8359.1 µs ( 6.9), set: 12555.9 µs ( 4.3) ets (set) get: 6100.3 µs ( 5.0), set: 16166.7 µs ( 5.6) ets x10 read (ordere get: 5045.8 µs ( 4.1) ets x10 read (set) get: 3196.1 µs ( 2.6) gb_trees get: 10767.4 µs ( 8.8), set: 120424.8 µs ( 41.7) hashtl get: 11302.7 µs ( 9.3), set: 25191.9 µs ( 8.7) process dictionary get: 2081.1 µs ( 1.7), set: 2890.8 µs ( 1.0) rbdict get: 11418.0 µs ( 9.4), set: 40875.7 µs ( 14.1) tuple get: 1219.9 µs ( 1.0), set: 2500319.5 µs (864.9) N == 32000 (10 runs) aadict get: 24278.9 µs ( 9.9), set: 96279.2 µs ( 12.1) array (dynamic) get: 19642.4 µs ( 8.0), set: 47917.9 µs ( 6.0) array (fixed) get: 19781.2 µs ( 8.1), set: 39503.3 µs ( 5.0) dict get: 19155.6 µs ( 7.8), set: 237609.2 µs ( 29.9) ets (ordered_set) get: 18021.3 µs ( 7.4), set: 25457.2 µs ( 3.2) ets (set) get: 14420.6 µs ( 5.9), set: 33051.4 µs ( 4.2) ets x10 read (ordere get: 10584.6 µs ( 4.3) ets x10 read (set) get: 7193.0 µs ( 2.9) gb_trees get: 23442.1 µs ( 9.6), set: 244698.6 µs ( 30.8) hashtl get: 25704.7 µs ( 10.5), set: 47058.7 µs ( 5.9) process dictionary get: 4151.9 µs ( 1.7), set: 7941.7 µs ( 1.0) rbdict get: 23069.3 µs ( 9.4), set: 85377.7 µs ( 10.8) tuple get: 2447.1 µs ( 1.0), set: 10227316.7 µs (*****) N == 64000 (10 runs) aadict get: 47719.6 µs ( 9.8), set: 225636.9 µs ( 14.4) array (dynamic) get: 38896.1 µs ( 8.0), set: 88107.9 µs ( 5.6) array (fixed) get: 38844.9 µs ( 8.0), set: 91707.1 µs ( 5.8) dict get: 38987.5 µs ( 8.0), set: 722098.9 µs ( 46.0) ets (ordered_set) get: 38267.4 µs ( 7.8), set: 54992.6 µs ( 3.5) ets (set) get: 35880.6 µs ( 7.3), set: 71159.9 µs ( 4.5) ets x10 read (ordere get: 22375.3 µs ( 4.6) ets x10 read (set) get: 17203.7 µs ( 3.5) gb_trees get: 49406.1 µs ( 10.1), set: 522021.5 µs ( 33.3) hashtl get: 40078.7 µs ( 8.2), set: 107626.0 µs ( 6.9) process dictionary get: 8210.2 µs ( 1.7), set: 15697.8 µs ( 1.0) rbdict get: 48208.3 µs ( 9.9), set: 216548.6 µs ( 13.8) tuple get: 4883.4 µs ( 1.0), set: 50572301.0 µs (*****)