Re: WIP: Covering + unique indexes.

08.04.2016 15:06, Teodor Sigaev:
>> On Wed, Apr 6, 2016 at 1:50 PM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
>>> Personally, I like documenting assertions, and will sometimes write
>>> assertions that the compiler could easily optimize away. Maybe going
>>> *that* far is more a matter of personal style, but I think an
>>> assertion about the new index tuple size being <= the old one is just
>>> a good idea. It's not about a problem in your code at all.
>>
>> You should make index_truncate_tuple()/index_reform_tuple() promise to
>> always do this in its comments/contract with caller as part of this,
>> IMV.
>>
> Some notices:
> - index_truncate_tuple(Relation idxrel, IndexTuple olditup, int indnatts,
> int indnkeyatts)
> Why we need indnatts/indnkeyatts? They are presented in idxrel struct
> already
> - follow code where index_truncate_tuple() is called, it should never
> called in
> case where indnatts == indnkeyatts. So, indnkeyatts should be
> strictly less
> than indnatts, pls, change assertion. If they are equal the this
> function
> becomes complicated variant of CopyIndexTuple()

Good point. These attributes seem to be there since previous versions of
the function.
But now they are definitely unnecessary. Updated patch is attached

--
Anastasia Lubennikova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company