Working with basic raster information and analysis

So far, we've checked and imported the PRISM and SRTM rasters into the chp05 schema of the postgis_cookbook database. We will now proceed to work with the rasters within the database.

Getting ready

In this recipe, we explore functions that provide insight into the raster attributes and characteristics found in the postgis_cookbook database. In doing so, we can see if what is found in the database matches the information provided by accessing gdalinfo.

How to do it...

PostGIS includes the raster_columns view to provide a high-level summary of all the raster columns found in the database. This view is similar to the geometry_columns and geography_columns views in function and form.

Let's run the following SQL query in the raster_columns view to see what information is available in the prism table:

SELECT 
  r_table_name, 
  r_raster_column, 
  srid, 
  scale_x, 
  scale_y, 
  blocksize_x, 
  blocksize_y, 
  same_alignment, 
  regular_blocking, ...