[postgis-users] pgchip

Paul Ramsey pramsey at refractions.net
Fri Dec 16 08:57:33 PST 2005


Simon Benjamin has added a link <http://simon.benjamin.free.fr/pgchip/ 
 > to pgchip (we knew someone would do it eventually!) on the wiki  
<http://postgis.refractions.net/support/wiki>.

Simon, one of the fiddlier problems with rasters once you get them  
into the database is random access... for our *only* raster-in- 
database project, we cut the rasters up into small chunks below the  
page size, so that we could quickly pull together the chunks we  
needed.  That meant that a single input raster could be exploded into  
thousands of storage chips (hence the type name).  Are you chipping  
or stuffing?  The trouble with chipping is that it requires a de- 
chipper in order for the stored data to be at all useful (see, raster  
in arcsde, which uses the same trick, and dechips in arcmap or arcims).

P.