On 10/5/06, Jean-Christophe Roux <jcxxr@xxxxxxxxx> wrote:
Why would I set a bytea column (containing picures) as a primary key? Because I want to be sure that the same image is inserted only once (that requirement comes from a real project) and using a primary key for that purpose makes sense to me. Am I going to retrieve an image row by its image data? I would certainly like! For instance, I would like to get the pictures whose main color is green (requirement from a real project), and a select * from images where main_color(image) = 'green' would be nice. JCR
standard postgresql indexes use a btree which would be completely impractical to index bitmaps. what you would want is a hand rigged unqiue constraint which is combination of insert trigger and hash algorithm plus some code to resolve collisions. this is what i would do if bitmaps were stored in/out of the database. merlin
