Re: hash index improving v3

Alex Hunsaker napsal(a):

>
> wide:
> # NOTE not on the same machine as the "narrow" test was run!
>
> # spit out 2, 000, 000 random 100 length strings
> perl gen.pl > data.sql
> create table test_hash (wide text);
> copy test_hash from './data.sql';
> create index test_hash_num_idx on test_hash using hash (wide);
>
> bench.sql:
> select a.wide from test_hash as a inner join test_hash as b on b.wide
> = a.wide where a.wide =
> 'BJNORSLMITGKHJCWDBLKLYRSJTVPTYXZJPWNBKXGHYFNDHRAKNFMDHRMUXLDXNTRBJMTHPGPBFJZPAENZXDHAHCUSCJTUPUXWCXUH';
>
> # ^ that string is in data.sql
>
> # 3 runs each
> pgbench -c1 -n -t100000 -f bench.sql
> cvs head: tps = 5073.463498, 5110.620923, 4955.347610
> v5:           tps = 5870.681336, 5740.007837, 5699.002942

What locale did you use? It would be nice to have also comparing between
C and any UTF8 locale. I think we should see big benefit when non C
locale is used.

        Thanks Zdenek