[Tilesathome] t at h server performance

[Martijn van Oosterhout]

On Dec 22, 2007 8:30 PM,  <milenko at king-nerd.com> wrote:
> What's the disadvantage to just storing the blank tiles?  If my maths are correct, 35,000,000 300byte tiles would be 143,360,000,000 bytes on disc (assuming 4096 byte clusters).  Divide by 1024 and 1024 and 1024 to get GB and I get 133.51GB.  That doesn't seem like it would be impossible to do.

Umm, there's 35 million tiles now. However, over the whole world there
are going to be on the order of 2^34 (approx 16x10^9) blank tiles,
Think of the sea and everything not mapped yet. 300 bytes per tile is
optimistic since you have a directory entry plus an inode for each,
plus any slack space in the block. If you take 0.5KB per tile gives
you 8x10^9KB or 8000Gigabytes. Add another 35% for all the other zoom
levels puts you at about 11petabytes. And I think that's optimistic.

The whole point of the exercise is to not store all those. Doesn't
really matter how, just need to find a way.

Have a nice day,
-- 
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/