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Category: Low Cost Mapping
Searching for information on why PostGIS may be be a better option for storing raster data, I came across a presentation "Advanced spatial analysis with PostGIS" by Pierre Racine from the FOSS4G conference earlier this year. The presentation as a whole is chock full of intriguing ideas and the summary below sealed the deal for me on using PostGIS for large raster data sets.

In summary:

Why store raster in the database?

  • One simple language for everything: SQL
  • Many raster functions are similar to vector ones...Complex spatial analyses can be done with a single SQL query.
  • Raster/Vector interaction -Your vector data are normally already in the database...
  • Performance Analysis processing is generally faster on tiled raster coverage.
  • Data volume - You can work on TB raster coverages without much problems.
  • You can even keep the raster’s data outside the database... ...and use them transparently inside the db with SQL
  • Only metadata are stored inside (extent, SRID, pixel type, nodata) Pixel values area read from the referenced files via GDAL.
  • raster2pgsql –R option