[OSM-dev] Lean and mean Tile- and XML-API-Server

[Stefan de Konink]

Matt Amos wrote:
> ah well, thats the price you pay for being able to easily write code
> without having to manage memory manually (or stick shared_ptr<> all
> over the place). there is a bug in there too, i think, which results
> in libxml not fully free()ing all the memory it is using.

Come on you can give better arguments than that :) C/C++ is not a 
prototype language. You will need to have your functional diagrams ready 
before start 'scripting'. So I don't mind pointers, and in this case my 
webserver's api takes care of the string management, so I am a happy 
coder :)

>>> the database is currently the bottleneck and i'm pretty sure they
>>> already wrote that in C :-)
>> The database that is used in production isn't the most efficient one too ;)
>> So that is also optimised ;)
> 
> how did you optimise it? (other than converting ways to relations)?

Not using MySQL, but MonetDB. It uses column based storage.

>> Double: 50~100ms
>> Integer: 40~80ms
>>
>> But the calltrace revealed in both search situation more optimisations where
>> possible.
> 
> 20% is pretty significant. obviously thats an optimisation worth having.

Jup, but extra mathematical overhead in query generation that should not 
be forgotten. Every output has to be atoi -> double back. And in the 
case of storing doubles/floats the input can directly be passed to the 
user. I need to figure out if the overhead of data translation is not 
bigger than querying speed.


Stefan