[OSM-dev] OSM Database schema

[Lorenzo Stucchi]

Hi all,

I have almost complete the explanation of the schema regarding the element (node, way and relation) I have just one last element to be understood.

The “tile” in the node table. I found in the code a function called “public.tile_for_point” [1] and seems that should be the one that do this process. But I’m not able to understood which is the output of the function, in particular what this part of code does:

x := (x | (x << 8)) & 16711935; — 0x00FF00FF

Thanks for all the reply.

Best,
Lorenzo

[1] https://github.com/openstreetmap/openstreetmap-website/blob/751e8ad32c864f50eae9e9359d74a11dc44de007/db/structure.sql#L160

Il giorno 10 gen 2020, alle ore 15:51, Lorenzo Stucchi <lorenzostucchi95 at outlook.it<mailto:lorenzostucchi95 at outlook.it>> ha scritto:

Thanks for the reply.

Is this the formula [1] ?

Best,
Lorenzo

[1] https://github.com/openstreetmap/openstreetmap-website/blob/751e8ad32c864f50eae9e9359d74a11dc44de007/db/structure.sql#L160

Il giorno 10 gen 2020, alle ore 15:22, Frederik Ramm <frederik at remote.org<mailto:frederik at remote.org>> ha scritto:

Hi,

On 10.01.20 15:08, Lorenzo Stucchi wrote:
What does it mean the “timestamp” present in the table (“node", “way" and “relation")?

When the object was last changed.

What does it mean the “tile” element present in the “node" table?

An integer derived from the lat/lon of the node using a mathematical
formula.

What does it mean the “sequence_id” in the “way_nodes” table and “relation_member” table?

An integer used to store the ordering of the nodes/members (which node
is the first, the second, ... in the way).

Bye
Frederik

--
Frederik Ramm  ##  eMail frederik at remote.org<mailto:frederik at remote.org>  ##  N49°00'09" E008°23'33"

_______________________________________________
dev mailing list
dev at openstreetmap.org<mailto:dev at openstreetmap.org>
https://lists.openstreetmap.org/listinfo/dev

_______________________________________________
dev mailing list
dev at openstreetmap.org<mailto:dev at openstreetmap.org>
https://lists.openstreetmap.org/listinfo/dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/dev/attachments/20200114/f2b6c501/attachment.htm>