ST_CreateOverview — Create an reduced resolution version of a given raster coverage.


regclass ST_CreateOverview(regclass tab, name col, int factor, text algo='NearestNeighbor');


Create an overview table with resampled tiles from the source table. Output tiles will have the same size of input tiles and cover the same spatial extent with a lower resolution (pixel size will be 1/factor of the original in both directions).

The overview table will be made available in the raster_overviews catalog and will have raster constraints enforced.

Algorithm options are: 'NearestNeighbor', 'Bilinear', 'Cubic', 'CubicSpline', and 'Lanczos'. Refer to: GDAL Warp resampling methods for more details.

Availability: 2.2.0


Output to generally better quality but slower to product format

SELECT ST_CreateOverview('mydata.mytable'::regclass, 'rast', 2, 'Lanczos');

Output to faster to process default nearest neighbor

SELECT ST_CreateOverview('mydata.mytable'::regclass, 'rast', 2);

See Also

ST_Retile, AddOverviewConstraints, AddRasterConstraints, Section 5.2.2, “Raster Overviews”