Re: WIP: Covering + unique indexes.

08.04.2016 15:45, Anastasia Lubennikova:
> 08.04.2016 15:06, Teodor Sigaev:
>>> On Wed, Apr 6, 2016 at 1:50 PM, Peter Geoghegan <pg@heroku.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

One more improvement - note about expressions into documentation.

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