[OSM-dev] Daily Planet.osm

Jon Burgess jburgess777 at googlemail.com
Mon Apr 30 12:42:08 BST 2007

On 30/04/07, Schuyler Erle <schuyler at nocat.net> wrote:
> * On 30-Apr-2007 at  3:12AM PDT, Nick Whitelegg said:
> > >Incremental dumps already have been discussed. I think it is a good
> > >solution for the following reasons :
> >
> > My only concern (and this may not be a real issue) is that it would
> > require more memory to patch a planet.osm than just convert it to SQL -
> > and if it does, they will be more difficult to deal with on systems with
> > restricted memory. This may be a completely false assumption though.

If you are thinking about the planetdiff/planetpatch tool that I put
into SVN, then this has uses a pure streaming model with constant
memory usage.

> If one is importing to a database, then using David Earl's suggestion
> of serializing the incremental dump in the form of
> insert/update/delete changes should result into an import process with
> a constant memory footprint. If the serialization is XML, a SAX parser
> will be necessary, also.

yes - it would be better if tools which use the planet.osm could take
an incremental update directly since it would reduce the CPU/memory
effort of performing an update.


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