Re: [HACKERS] [PATCH] kNN for SP-GiST

Hi!

> 14 июля 2018 г., в 1:31, Nikita Glukhov <n(dot)gluhov(at)postgrespro(dot)ru> написал(а):
>
> Attached 6th version of the patches.
> ...
>> 2. The patch leaves contribs intact. Do extensions with sp-gist opclasses
>> need to update it's behavior somehow to be used as-is? Or to support new
>> functionality?
>
> There are no SP-GiST opclasses in contrib/, so there is nothing to change in
> contrib/. Moreover, existing extensions need to be updated only for support of
> new distance-ordered searches -- they need to implement distances[][] array
> calculation in their spgInnerConsistent() and spgLeafConsistent() support
> functions.
So, if extension will not update anything - it will keep all preexisting functionality, right?

I have some more nitpicks about naming
+ recheckQual = out.recheck;
+ recheckDist = out.recheckDistances;
Can we call this things somehow in one fashion?

Also, this my be a stupid question, but do we really need to differ this two recheck cases? It is certain that we cannot merge them?

This seems strange if-formatting
+ /* If allTheSame, they should all or none of 'em match */
+ if (innerTuple->allTheSame)
+ if (out.nNodes != 0 && out.nNodes != nNodes)
+ elog(ERROR, "inconsistent inner_consistent results for allTheSame inner tuple");
+
+ if (out.nNodes) // few lines before you compare with 0

Best regards, Andrey Borodin.