Size op       perl       GDBM       NDBM       ODBM       SDBM    DB_File   CDB_File  LMDB_File
------ -- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
    20 rd  1666666.7     4419.9     8025.7     8650.5     6004.2     4342.2     4396.6     6968.6
    20 wr  1818181.8     5383.6     9058.0    11160.7     9049.8     4965.2     6583.3     7479.4
   200 rd  1754386.0    30599.8    53092.6    57388.8    63938.6    28835.1    55157.2    37828.6
   200 wr  2409638.6    34764.5    67181.7    60024.0    49627.8    36832.4   124223.6    57028.8
   600 rd  1785714.3    92081.0   100654.3   110436.2   130378.1    91185.4   150564.6    63151.2
   600 wr  2857142.9    83114.0   116369.3   128287.4    76036.0    92692.7   307219.7   108303.2
  2000 rd  1806684.7   221877.1   186968.3   189969.6   200541.5   157257.4   315059.9    74881.1
  2000 wr  2656042.5   217793.7   188076.0   206015.7    96459.9   219442.6   623830.3   146166.8
 20000 rd  1225565.3   217185.9   174087.1   162620.1   164974.3   132289.1   418550.1    74129.5
 20000 wr  1623640.2   176447.8   160959.3   156257.3   107578.9   134935.5   800768.7   139251.5
200000 rd   528887.9   162823.0   147817.9   132551.1   131489.6   107172.2   373562.3    67801.9
200000 wr   656525.5    83695.0    82843.5    84043.8   101899.1    79178.1   587721.9   131520.2