Re: GiST: PickSplit and multi-attr indexes

On Mon, 2004-11-15 at 10:19 -0500, Tom Lane wrote:
> I'm not familiar with the details of the GiST code, but would it work to
> generalize PickSplit to return a three-way classification? That is,
> instead of actually splitting the node, have it identify each item as
> "definitely left", "definitely right", or "don't care" (think "less",
> "greater", or "equal to" the desired split value).

I had thought about this solution, but I was worried that it will
actually make GiST a less general framework, because it requires that
the PickSplit() method effectively order the leaves of the tree. For
btree that is a reasonable assumption to make, but I'm not sure if it
can or should be made in general.

That said, I haven't actually implemented any indexes using GiST;
perhaps Oleg or Teodor can comment?

-Neil