Yes, but after you do such a select, you can't save this simplified line back to OSM.
Is it different from SELECT tags, ST_AsGeoJSON(ST_SimplifyPreserveTopology(ST_RemoveRepeatedPoints(way, 1000), 10000)) from planet_osm_polygon where name='United States of America' and boundary='administrative'; In osm2pgsql imported with --hstore-all key? ср, 16 нояб. 2016 г. в 7:30, RTOSM DOOPAS <rtos...@gmail.com>: > Yes, osm2pgsql/imposm are very useful tool. > > While the osm2pgsql and imposm are used to import data from API > Database to a PostGIS instance. With the PostGIS, user can perform > tile rendering or geospatial computing. > > The purpose of the osm2pgsql/imposm is different. rtosm aims to make > the API database more flexible and versatile to have the ability to > answer following queries : > > "select the national boundary of U.S. in 1000 (or any other number, > you name it) nodes and tell the simplification error of it" > > So user can draw any huge features in real-time in browser or JOSM > with its simplified version. the online data editing and online data > viewing can be more efficient. > > let's take an example, The relation with ID 6038068 (islands of > Britain) is comprised by 4596 ways and 634414 nodes. without > simplification, even with a naive simplification which only preserve > the start and end point of of each way will result in 4596 nodes to > represent the feature, it is hard to visualized and manipulated with > so many nodes retrieved from database. The rtosm can simplify the > relation with any number of nodes. > > In short, rtosm is about to extend the OSM API to make it support > viewing and editing data at any scale directly from database. > > On Wed, Nov 16, 2016 at 6:36 AM, Darafei "Komяpa" Praliaskouski > <m...@komzpa.net> wrote: > > Hi! > > > > Have you tried osm2pgsql and/or imposm? What is the reason to do it over > API > > db schema? > > > > вт, 15 нояб. 2016 г. в 19:27, RTOSM DOOPAS <rtos...@gmail.com>: > >> > >> Hi, > >> > >> > >> > >> I have written a small extension for OSM API database to offer the > >> functionality of real-time simplification of objects (ways, relations) > by > >> node filtering during the query processing. The idea behind it is as > >> followings: > >> > >> > >> 1. For each spatial object such as way or relation, attach weight value > to > >> each component node by geometric computation. > >> > >> > >> 2. In processing query, only retrieve nodes with the top k weight. > >> > >> > >> 3. Assembly the simplified objects with filtered nodes. > >> > >> > >> > >> In fact, there are some really complex concepts, algorithms and data > >> structures in the extension, but the essential idea is that simple. > >> > >> > >> With this extension, The OSM API database will have the ability to > answer > >> windowing query with arbitrary size by a “top k” operator to limit the > >> output volume of the results. > >> > >> > >> The purpose of the extension is to make the OSM API database can serve > >> data in any scale like the tile server can do. > >> > >> > >> The codes in the extension is a bit of preliminary. However, to make > the > >> idea work, Not only the code need to be examined and tested, but also > the > >> database must be “normalized” to take the advantages of this extension. > >> > >> > >> The code is hosted in github, https://github.com/rtosm/rtosm > >> > >> > >> The "rtosm" means a database for real-time openstreetmap. Welcome to > >> comment. > >> > >> _______________________________________________ > >> dev mailing list > >> dev@openstreetmap.org > >> https://lists.openstreetmap.org/listinfo/dev >
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