knngist patch support

I noticed this morning that the k nearest neighbor gist patch https://commitfest.postgresql.org/action/patch_view?id=230 was still being considered for inclusion in 9. Sadly, this feature appears to have been dropped from 9.

It seems to me that the functionality this brings is one of the most common use cases for mobile applications (or even web in some cases) that are location enabled. How many times do we find ourselves "Finding the 10 nearest restaurants" in our smart phones? Well, this patch solves exactly that in the most efficient manner.

Granted, one can currently solve this problem with PostgreSQL/PostGIS as it stands, however the performance improvements that one can gain for those types of (extremely common) queries leveraging the Gist enhancements are, well, exciting. 

300x time improvements? Sounds great to me.

I would love if you guys could consider applying this patch for this upcoming release.

Best Regards,

- Ragi Burhum