Re: pgsql: Add deduplication to nbtree.

On Sun, Mar 1, 2020 at 11:29 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Hm. That would probably be enough to shut up Coverity, but I'm unsure
> whether it'd really be an improvement from the legibility and safety
> viewpoints.

I noticed that _bt_update_posting() behaves as if the origtuple might
not be a posting list tuple at the point that keysize is calculated,
despite generally depending on it being a posting list tuple (which it
asserts by way of its "_bt_posting_valid(origtuple)" assertion). The
final tuple might not be a posting list, but the original one must be
(if it isn't, then nbtree VACUUM should be deleting it outright in the
traditional way, rather than updating it). I should fix that, either
way.

> Do you want to try coding it that way and see what it
> comes out like?

Sure.

--
Peter Geoghegan