[OSM-dev] Osmosis multi-task questions

[Frederik Ramm]

Hi,

   tanks for the comments -

> If you want to use default pipe connection, you'll have to do something 
> like this.

> osmosis
>     --rx
>     --tee 20
>     --bp file=poly01.txt
>     --bp file=poly02.txt
>     ...
>     --bp file=poly20.txt
>     --wx out01.osm
>     --wx out02.osm
>     ...
>     --wx out20.osm
> 
> Note that paired tasks are not next to each other on the command line, 
> the tee registers 20 outputs, the --bp tasks read each of those and 
> produce another 20 outputs, the --wx tasks then pick each of those up 
> and write to file.

Ah! I would have thought that the second --bp would immediately
consume the output created by the first --bp in this case.

> With a decent machine, I think you'll find file based performance more 
> than adequate.  A file will be far quicker than using MySQL as raw data 
> storage without using any indexing.  If bounding boxes could be 
> extracted directly from the db it may be quicker, it's not something 
> I've tried.  A new mysql task for reading bounding boxes directly from a 
> db could be very useful, patches welcome of course :-)

I'll see if I can come up with something. From past experience I fear
that even inserting a planet into Mysql might take more time than the
whole file-based operation, in which case it might not be worth the
bother. But my setup will give us interesting test scenarios at least.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00.09' E008°23.33'