On Fri, Oct 27, 2017 at 9:54 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Robert Haas <robertmhaas@gmail.com> writes: > On Thu, Oct 26, 2017 at 12:22 PM, Andrey Borodin <x4mmm@yandex-team.ru> wrote: >> For cube there is new default opclass.
> I seem to recall that changing the default opclass causes unsolvable > problems with upgrades. You might want to check the archives for > previous discussions of this issue; unfortunately, I don't recall the > details off-hand.
Quite aside from that, replacing the opclass with a new one creates user-visible headaches that I don't think are justified, i.e. having to reconstruct indexes in order to get the benefit.
Maybe I'm missing something, but ISTM you could just drop the compress function and call it good. This would mean that an IOS scan would sometimes hand back a toast-compressed value, but what's the problem with that?
+1,
I think in this case replacing default opclass or even duplicating opclass isn't justified.
(The only reason for making a decompress function that just detoasts is that your other support functions then do not have to consider the possibility that they're handed a toast-compressed value. I have not checked whether that really matters for cube.)
As I can see, cube GiST code always uses DatumGetNDBOX() macro to transform Datum to (NDBOX *).
