Even Rouault-2 wrote > Yuta, > > Increasing GDAL_CACHEMAX might accelerate in case of repeated reads on > windows > that are identical or overlapping already read windows. Or if the way you > read > the raster doesn't follow its block shape : for example if the raster is > organized by lines/strips and you read by square blocks, or the reverse > situation. > > GDAL_SWATH_SIZE is only used by CreateCopy(). > > Even
Interesting, thanks for mentioning this. The case you mention might seem like bad practice, but it still true that VRT's only allow blocks of 128x128 right? VRT's are something i use all the time. And for example, Landsat geotiff's from the USGS are delivered as stripes of '1 by width'. If performance is really an issue i sometimes deliberately read chucks of '128 x width' in order to avoid the inefficiency. I'll try to see if increasing the CACHE_MAX might do this 'on the fly' without me having to worry about the alignment of the block definitions. Regards, Rutger -- View this message in context: http://osgeo-org.1560.x6.nabble.com/gdal-dev-ReadAsArray-tp5196714p5200255.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
