On 2020-01-04 09:59, Lorenzo Stucchi wrote: > Thank you Pascal. This is can be more precise than just I looking at the > visualisation [1].
I'm not aware of a comprehensive data model internals documentation beyond the actual source code in https://github.com/openstreetmap/openstreetmap-website, in particular the app/*/api directory > > But, for example, what is the “timestamp” in the “node" table? It refers to the current time in UTC when the node create/update/delete operation was executed. Please see https://github.com/openstreetmap/openstreetmap-website/blob/master/app/models/node.rb#L243 > And what is the “redactions” table? It contains a list of reasons why an object has been redacted, see https://www.openstreetmap.org/redactions - the actual objects (such as nodes, ways, relations) refer to this redaction table via the redaction_id. > Or, why in the “way_nodes” table there is > “version", but also it is just a link to the “nodes” table that contains > also the “version” attribute. Basically there are two different sets of tables: the current_* ones, and the historic ones. "way_nodes" belongs to the historic set of tables, and you need the version attribute to know that a node was part of say version 2 of way 12345. On the other hand, the current_way_nodes table has no version attribute, as it assumes that it refers to the latest version of an object. > > For this reason, I was trying to look to an explanation of this schema > if it exists. I think one good way to find out more about those different tables is to install a local version of the Rails port and do some edits via iD/JOSM/Potlatch. The Rails port is quite verbose and lists every single database operation on the console. -- _______________________________________________ dev mailing list dev@openstreetmap.org https://lists.openstreetmap.org/listinfo/dev
