[OSM-dev] Proposal: Database accelerator and dirty tile marker based on simple algorithm.

[Nick Hill]

Lars Aronsson wrote:
> Nick Hill wrote:
> 
>> I think I understand that you are saying the character based system 
>> enables a description of a larger tile by using fewer characters.
> 
> The cache invalidation-upon-write issue is interesting.  How large 
> are the tile caches that Squid holds today?  As far as I 
> understand, there should be three such caches today:
> 
>  1. Raw background Landsat images.
>  2. Landsat images with roads drawn.
>  3. Yellow marks for GPS tracklogs, used by the Java applet.

Total cache on tile is currently 14Gb. Probably least recently used 
flush for 1. Probably time based for 2 and 3.

I have a new machine for the caching. Has 400Gb.