[OSM-dev] ER Diagram of OSM Database

Toby Murray toby.murray at gmail.com
Tue Dec 13 05:31:11 GMT 2011


Well there aren't any database level foreign key constraints in the
osm2pgsql schema so database visualization tools won't give you
anything useful to look at. Each table is its own island. This schema
is denormalized for rendering performance and the import process is
lossy. Only objects defined in the style are imported. Everything else
is ignored. The wiki page explains things a little although it could
use some cleanup by someone who is more familiar with it. Phrases like
"I noticed these tables being present after an import in slim mode.
They seem to be for the first import stage" don't exactly inspire
confidence...

http://wiki.openstreetmap.org/wiki/Osm2pgsql/schema

Toby


On Mon, Dec 12, 2011 at 10:20 PM, Parveen Arora <mail at parveenarora.in> wrote:
> On Mon, Dec 12, 2011 at 4:14 PM, Andreas Hubel <andi at saerdnaer.de> wrote:
>> Hello Parveen,
>>
>> Am 12.12.2011 um 19:50 schrieb Parveen Arora:
>>> I was searching for ER Diagram of OpenStreetMap's Database to
>>> understand completely,
>> I think the best way is to understand the different parts step by step and not to try to understand everything at the first time.
>>
>>> I found one component diagram
>>> http://wiki.openstreetmap.org/wiki/Component_overview
>>>
>>> But I want one only of database?
>> There is not one database. The main services provided by the foundation actually use two different databases, as shown in the component overview you already found.
>> Green: PostgreSQL backend
>>        aliases: api db, main db, core db
>> Yellow: PostGIS
>>        aliases: osm2pgsql db, Mapnik db
> Yes, I want to have the diagram Yellow:PostGIS, the diagram of
> database of osm file stored using osm2pgsql.
>
>
>> We should definitely discuss about using uniform names in future.
> Yes, I realized this lately after posting the email, I will take care
> of it from next time.
>
>
>
> Thank You.
>
>
>
>
> --
> Parveen Arora
> www.parveenarora.in
> E-Mail: mail at parveenarora.in
>
> _______________________________________________
> dev mailing list
> dev at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/dev



More information about the dev mailing list