Re: Covering GiST indexes

On Thu, Apr 12, 2018 at 4:00 AM, Andrey Borodin <x4mmm(at)yandex-team(dot)ru> wrote:
> I have two concerns.
> First one is about INDEX_AM_RESERVED_BIT.
> B-tree uses it as a base for prefix truncation (I'm not quite sure why it is usually called suffix truncation, but this is a matter for other thread).

Since you brought it up, and since I pushed that particular
terminology, I should acknowledge that the original 1977 Bayer paper
on suffix truncation calls a B-Tree with suffix truncation a prefix
B-Tree. However, more recent work seems to consistently refer to the
technique as suffix truncation, while also referring to more advanced
techniques for compressing (not truncating) leaf tuples as prefix
compression.

I suggested suffix truncation because it seemed to be the dominant way
of referring to the technique. And, because it seemed more logical:
the suffix is what gets truncated away.

--
Peter Geoghegan