GIT patch

Hi,

I've started reading the GIT patch to see if I can help with the review.
First thing I notice is that there are several things that seems left
over; for example the comments in pg_proc for the new functions are
incomplete.

More subtle: in _bt_findinsertloc, the test for
modifiedpage = _bt_groupify() may reset the bit set by the
_bt_vacuum_one_page.  Surely it should look like

modifiedpage |= _bt_groupify() 

There's also a couple of spots that were not merged cleanly, but since
they were inside comments, the compiler did not complain and so were not
fixed.

I'm also finding a certain lack of code commentary that makes the
reviewing a bit harder.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support