Re: GiST "choose subtree" support function to inline penalty

Hi!

> 24 июня 2019 г., в 15:08, Darafei Komяpa Praliaskouski <me@komzpa.net> написал(а):
>
> I'm looking at PostGIS geometry GiST index build times and try to optimize withing the current GiST framework. The
functionthat shows a lot on my flame graphs is penalty.  
>
> I spent weekend rewriting PostGIS penalty to be as fast as possible.
> (FYI https://github.com/postgis/postgis/pull/425/files)
>
> However I cannot get any meaningfully faster build time. Even when I strip it to "just return edge extension" index
buildtime is the same. 
>
> Is there a way to inline the penalty into above "choose subtree" loop somehow? That would also let us stop
bit-fiddlingfloats to simulate a more complex choosing scheme. 

Maybe we could just add new opclass function for choosing subtree?
I've created GSoC item for this[0].


Best regards, Andrey Borodin.

[0] https://wiki.postgresql.org/wiki/GSoC_2019#GiST_API_advancement_.282019.29