On 2018-11-25 5:50 AM, Victor Shcherb wrote:
What do you think?
It would be terrible for most software that I am aware of that can process the full planet. Current assumptions about density would be broken, vastly inflating memory usage and slowing down processing.
The benefits aren't great as I see them. Using a z-order curve encoded in the first 30 bits will help cache locality, but like all z-order curves, it doesn't guarantee that two nearby places in 2d space have nearby places on the curve. This means that an implementation still needs to be able to search through the nodes for nearby ones.
Two other problems come to mind. The first of these is implementation. IDs are a PostgreSQL bigserial, and to write something custom that assigns IDs based on location would be difficult as it would need to get MVCC right. The second is the number of bits. Some software is limited to 53-59 bits, and other to 63 bits. We're using about 75% of 33 bits right now.
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