Changes between Version 28 and Version 29 of WKTRaster/SpecificationWorking01


Ignore:
Timestamp:
May 29, 2009, 8:09:37 AM (15 years ago)
Author:
mloskot
Comment:

Linked overviews discussion

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  • WKTRaster/SpecificationWorking01

    v28 v29  
    277277
    278278If the RASTER_COLUMNS "regular_blocking" value is true then "all blocks are equal sized, abutted and non-overlapping, started at top left origin", plus additional constraints. This regular blocking capability raises the possibility of having very large contiguous raster coverages (made up of many individual WKTRaster-s) which, in turn, raises potential performance problems. Other raster formats counter this by having overviews; a concept that is already [http://www.gdal.org/gdaladdo.html supported] by [http://www.gdal.org/ GDAL].
     279
     280The overviews support was discussed on Martin Daly's initiative and is available in the [http://postgis.refractions.net/mailman/listinfo/postgis-devel postgis-devel] archives under thread [http://postgis.refractions.net/pipermail/postgis-devel/2009-May/005619.html WKTRaster & overviews].
    279281
    280282The following metadata table provides external applications and possibly internal tools the ability to discover tables that contain overview raster data, and to learn various information about those datasets.