In order to reduce memory load at low zoom levels, it is useful for mapnik to request pre-scaling of rasters on the database side. In this way the required part of the raster is still fully loaded on the database side, but is then scaled and passed to tiler in a reduced size, possibly also discarding the full-resolution before sending it over.
Similarly, at high zoom levels, it is useful for mapnik to request pre-clipping of rasters on the databas side. In this way the required part of the raster is still fully loaded on the database side, but is then clipped and passed to tiler in a reduced size, possibly also disacarding the full-resolution before sending it over.
In order to reduce memory load at low zoom levels, it is useful for mapnik to request pre-scaling of rasters on the database side. In this way the required part of the raster is still fully loaded on the database side, but is then scaled and passed to tiler in a reduced size, possibly also discarding the full-resolution before sending it over.
Similarly, at high zoom levels, it is useful for mapnik to request pre-clipping of rasters on the databas side. In this way the required part of the raster is still fully loaded on the database side, but is then clipped and passed to tiler in a reduced size, possibly also disacarding the full-resolution before sending it over.