Hi, Please feed in your WKT polygons in EWKT format:
SRID=4326;POLYGON(...) Since every update in Postgres is essentially Delete+Insert, time of rewriting each and every row being equal to initial Insert time is expected thing. You can also update SRID in two columns in one go: update tablename set geom1 = ST_SetSRID(geom1, 4326), geom2 = ST_SetSRID(geom2, 4326); Out of curiosity, where did you learn about UpdateGeometrySRID before learning about ST_SetSRID? ср, 31 окт. 2018 г. в 21:57, jerry73204 <[email protected]>: > Hi all, > > I'm stuck in the low performance of UpdateGeometrySRID(). > > I get started with a 50GB polygon dataset in CSV in EPSG:4326 > coordinates. Since I find no way to `\copy` the csv while preserving the > SRID, the data is imported with null SRID and then `SELECT > UpdateGeometrySRID('table', 'column', 4326)`. > > The `UpdateGeometrySRID()` takes as long time as that of `\copy`, which > turns out to be approx two hours. The dataset has two geometry columns > and thus I have to take triple time to finish this data. > > I profiled the postgresql daemon. The avg disk writing speed is 30MB/s, > while occasionally peaks to 100MB/s. The SSD, F2FS formatted disk is > capable of up to 150MB/s. The daemon does not utilize the 4-core > i5-7600k CPU. It seems to be a single process task with avg CPU load > 20%, while other workers are idle. I wonder if there's a room for > improving the performance. Also, I'm looking for if it's possible to > preserve SRID with `\copy`. > > Jerry Lin > > _______________________________________________ > postgis-users mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/postgis-users -- Darafei Praliaskouski Support me: http://patreon.com/komzpa
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