Re: b-tree index search algorithms

Samuel Vogel <s@muel-vogel.de> writes:
> I'm currently on a university research project if performance could be 
> increased by substituting different inter-node search algorithms instead 
> of the currently used binary search.

Hm, what have you got in mind exactly?

> But I'm having troubles understanding how the general b-tree 
> implementation (nbtree.h) is used to represent for example a simple 
> primary key on an integer column. I've debug printed the 
> 'scankey->sk_argument' and all attributes of the index tuples on the 
> pages being traversed (simply ran 'DatumGetInt32' on both) but I never 
> see one of the integers actually appearing in my table being logged when 
> I do a select.

Not clear what you did wrong from this amount of detail, but integer
keys ought to be pretty obvious at the debugger level.

> This is why I assume that all column values are hashed before they are 
> pushed into the b-tree,

PG's b-trees do not hash anything.  If you're not seeing interpretable
key values then you're doing something wrong in your inspection
methodology.
        regards, tom lane