Re: B-Tree support function number 3 (strxfrm() optimization)

* Robert Haas (robertmhaas@gmail.com) wrote:
> On the PPC64 machine I normally use for performance testing, it takes
> about 6.3 seconds to build the index with the commit just before this
> one.  With this commit, it drops to 1.9 seconds.  That's more than a
> 3x speedup!
>
> Now, if I change the query that creates the table to this.
>
> rhaas=# create table stuff as select 'aaaaaaaa' || random()::text as
> a, 'filler filler filler'::text as b, g as c from generate_series(1,
> 1000000) g;
>
> ...then it takes 10.8 seconds with or without this patch.  In general,
> any case where the first few characters of every string are exactly
> identical (or only quite rarely different) will not benefit, but many
> practical cases will benefit significantly.  Also, Peter's gone to a
> fair amount of work to make sure that even when the patch does not
> help, it doesn't hurt, either.
>
> So that's pretty cool.

Wow, nice!

Good work Peter!
Thanks,
    Stephen