Size op       perl       SDBM   CDB_File  LMDB_File   KyotoCab     SQLite
------ -- ---------- ---------- ---------- ---------- ---------- ----------
    20 rd  1666666.7     7423.9     5614.8     6700.2     3478.9     7886.4
    20 wr  1666666.7     7806.4    13333.3     7902.0     2206.5     9775.2
   200 rd  1351351.4    62695.9    52952.1    39463.3    33984.7    45228.4
   200 wr  1709401.7    47494.7   134228.2    50314.5    15725.7    43131.3
   600 rd  2047781.6   138153.4   144092.2    66386.4    92893.6    66217.9
   600 wr  2884615.4    80699.4   281558.0   113938.5    70863.4    59970.0
  2000 rd  1901140.7   216849.2   297176.8    78929.7   119911.3    84613.1
  2000 wr  2649006.6    96098.4   575539.6   159083.7   143502.9    70526.8
 20000 rd  1274210.0   228574.0   509100.2    80934.3   109472.1    73961.5
 20000 wr  1649348.5   114533.8   863036.2   148118.5   198214.1    71024.7
200000 rd   534996.8   169792.5   485755.2    73310.5   107320.8    50125.8
200000 wr   661559.4    95249.5   673387.1   139133.0   218396.9    50760.9