Effect of hash table size with different inputs:

 select testname,
       (compresstest(data, niters, 8192)::numeric / 1000)::numeric(10,3) as hs8192,
       (compresstest(data, niters, 4096)::numeric / 1000)::numeric(10,3) as hs4096,
       (compresstest(data, niters, 2048)::numeric / 1000)::numeric(10,3) as hs2048,
       (compresstest(data, niters, 1024)::numeric / 1000)::numeric(10,3) as hs1024,
       (compresstest(data, niters, 512)::numeric / 1000)::numeric(10,3) as hs512,
       (compresstest(data, niters, 256)::numeric / 1000)::numeric(10,3) as hs256,
       (compresstest(data, niters, 128)::numeric / 1000)::numeric(10,3) as auto


     testname      |  hs8192   |  hs4096  |  hs2048  |  hs1024  |   hs512   |   hs256   |   hs128   
-------------------+-----------+----------+----------+----------+-----------+-----------+-----------
 5k text           |  1222.231 | 1264.006 | 1294.347 | 1467.306 |  1745.920 |  2126.767 |  3230.737
 512b text         |   843.599 |  798.738 |  767.920 |  778.185 |   843.600 |  1005.907 |  1341.928
 2k random         |  -846.911 | -807.785 | -850.312 | -949.990 | -1182.406 | -1697.588 | -2475.293
 100k random       |  -817.304 | -816.640 | -850.950 | -949.909 | -1186.656 | -1687.994 | -2463.968
 512b random       |  -616.751 | -590.581 | -589.250 | -594.732 |  -604.211 |  -673.908 |  -860.600
 64b of text       |  -695.125 | -529.532 | -437.263 | -396.065 |  -374.832 |  -368.065 |  -368.824
 64b random        | -1021.738 | -776.121 | -642.170 | -596.816 |  -543.020 |  -537.473 |  -533.326
 100k of same byte |  1174.348 | 1164.429 | 1140.323 | 1124.534 |  1135.122 |  1127.385 |  1127.968
 100k text         |   761.264 |  801.410 |  818.008 |  893.001 |  1020.317 |  1331.003 |  2008.104
(9 rows)
