Re: B-tree fan-out

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

Martijn van Oosterhout <kleptog(at)svana(dot)org> writes:
> On Fri, Jun 22, 2007 at 09:32:30PM +0200, cluster wrote:
>> In B-trees all non-leaf nodes have a bunch of pointers to its child
>> nodes. What is the size of such a pointer?

> I imagine it's a page number, probably just a 32-bit integer.

src/include/access/itup.h
Also see "Notes about data representation" in
src/backend/access/nbtree/README

We use the same tuple format for all entries in a btree.  The line
number part of the t_tid field is useless for downlinks, but in view of
alignment considerations this is unlikely to be worth worrying about.

			regards, tom lane