> > 10% is nothing. I was expecting this patch would give an order of
> > magnitude of improvement or somethine like that in the worst cases of
> > the current code (highly unsorted input)
>
> Yes. It should be x10 faster than ordinary method in the worst cases.
Here's my post with a (very simple) performance test:
http://archives.postgresql.org/pgsql-hackers/2010-02/msg00766.php
The test I used wasn't a "worst case" scenario, since it is based on
random data, not wrong-ordered data. Obviously, the real difference
can be seen on large tables (5M+ rows), and/or slow disks.
Leonardo