Re: B-Tree support function number 3 (strxfrm() optimization)

On Mon, Sep 15, 2014 at 10:17 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> It strikes me that perhaps we should make this change (rearranging
> things so that the memcmp tiebreak is run before strcoll) first,
> before dealing with the rest of the abbreviated keys infrastructure.
> It appears to be a separate improvement which is worthwhile
> independently of what we do about that patch.

I guess we could do that, but AFAICT the only open item blocking the
commit of a basic version of abbreviated keys (the informally agreed
to basic version lacking support for single-attribute aggregates) is
what to do about the current need to create a separate sortsupport
state. I've talked about my thoughts on that question in detail now
[1].

BTW, you probably realize this, but we still need a second memcmp()
after strcoll() too. hu_HU will care about that [2].

[1] http://www.postgresql.org/message-id/CAM3SWZQCDCnfWd3qzoO4QmY4G8oKHUqyrd26bBLa7FL2x-nTjg@mail.gmail.com
[2] http://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=656beff59033ccc5261a615802e1a85da68e8fad
--
Peter Geoghegan