This raster question comes up quite a bit on PostGIS mailing lists and stack overflow and the best answer often involvesthe often forgotten ST_Reclass function that has existed since PostGIS 2.0.
People often resort to the much slower though more flexible ST_MapAlgebra or dumping out their rasters as Pixel valued polygons they then filterwith WHERE val > 90, where ST_Reclass does the same thing but orders of magnitude faster.
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People often resort to the much slower though more flexible ST_MapAlgebra or dumping out their rasters as Pixel valued polygons they then filterwith WHERE val > 90, where ST_Reclass does the same thing but orders of magnitude faster.
Continue Reading by clicking title hyperlink ..
أكثر...