Re: Brain dump: btree collapsing

tom lane wrote:
> Hmmm ... that might be made to work, but it would complicate
> inserts. By the time an insert navigates to the page it
> should insert on, it might find the page is dead, and then it
> would have no easy way to get to the replacement page (unless
> you want to dedicate another link field in every index page
> for that one use). I suppose it could recover by starting
> the search over again.

Inserts could reread just the parent page if they encountered a dead
leaf since the parent would have been correctly updated.

> Another problem is that the two dead pages are now outside of
> the btree structure and so their left and right links won't
> get updated in the face of subsequent splits and merges of
> the nearby pages.

That seems like a "show stopper" that just defers the problem. A split
of the left sibling would still screw up a scan that was using the old
left leaf page and wanted to move left.

Oh, well, the idea seemed worth exploring.

- Curtis