Changes between Version 189 and Version 190 of WKTRaster/SpecificationWorking03

Timestamp:

Nov 29, 2011, 2:54:57 PM (12 years ago)

Author:

pracine

Comment:

—

WKTRaster/SpecificationWorking03

@@ -537 +537 @@
 PostGIS is using the typmod feature of PostgreSQL to 'store' metadata about a table and then display them in the geometry_column view. Unfortunately the typmod is limited to XXX bytes and there is too much information to 'store' about a raster table to use typmod. PostGIS raster will therefore use another approach consisting in 'storing' metadata about a raster table as constraint on the table. A set of constraint will be applied to a raster table and those constraint will be read and displayed by the raster_column view.
 
-The major changes concerning the raster_column table are as follow:
+The '''major changes concerning the raster_column table''' are as follow:
 
  * There will be a flexible !ApplyRasterConstraint() function trying to apply a set of constraint on a table. As for any constraint, each constraint will be successfully applied only when all the rows of the table fulfil this constraint. The list of potential constraint applied by the C loader (using the !ApplyRasterConstraint function) and hence the list of column available in the raster_column view will be: srid int, alignment (align on a upperleft x and y), scalex float8, scaley float8, width int, height int, numberofband int, pixeltypes text[], nodatavalues float[] in addition to the 'r_table_catalog', 'r_table_schema', 'r_table_name' and 'r_column' columns. There is still discussion about if global extent as a geometry should be added to this list. Comments are welcomes.
@@ -545 +545 @@
  * The raster_column view will derive columns of metadata from the constraints applied to each table listed. When a constraint does not exist (because it could not be applied successfully to the table by !ApplyRasterconstraint()), the column corresponding to this constraint for this table will be null.
 
-The major changes concerning the raster_overview table are as follow:
+The '''major changes concerning the raster_overview table''' are as follow:
 
  * The raster_overview table will also be replaced with a raster_overview view.
@@ -553 +553 @@
  * The raster_overview table will NOT be created by default by the rtpostgis.sql script. It will be the responsibility of applications to use the !ApplyOverviewConstraints and ST_CreateOverview() function to enable overviews support.
 
- The major changes concerning the raster2pgsql loader are as follow:
+The '''major changes concerning the raster2pgsql loader''' are as follow:
 
  * We are working on a new C importer to get rid of any Python, Numpy and Python GDAL binding dependency.