BUG #1252: Optimization of SELECT for NOT NULL case

The following bug has been logged online:

Bug reference:      1252
Logged by:          Alexander Kirpa

Email address:      postgres@bilteks.com

PostgreSQL version: 8.0 Beta

Operating system:   FreeBSD 5.2.1

Description:        Optimization of SELECT for NOT NULL case

Details: 

CREATE TABLE x (id int4 NOT NULL);
Populate table, for instance, 10M rows;
SELECT count(*) from x WHERE x IS NULL;
Optimizator should rewrite "x IS NULL" to simple "false"

Best regards,
 Alexander Kirpa