============================================================================
POSTGRESQL BUG REPORT TEMPLATE
============================================================================
Your name : Marko Mikulicic
Your email address : mmikulicic@full-moon.com
System Configuration
---------------------
Architecture (example: Intel Pentium) : Intel Pentium
Operating System (example: Linux 2.0.26 ELF) : Linux 2.2.13 ELF
PostgreSQL version (example: PostgreSQL-6.5.2): PostgreSQL-6.5.2
Compiler used (example: gcc 2.8.0) : pgcc-2.91.66
Please enter a FULL description of your problem:
------------------------------------------------
The SQL "intersect" construct returns an empty query in some cases
when some fields are null.
Please describe a way to repeat the problem. Please try to provide a
concise reproducible example, if at all possible:
----------------------------------------------------------------------
create table buggy ( a int, b int);
insert into buggy values ( 1);
insert into buggy values ( 2);
insert into buggy values ( 3);
insert into buggy values ( 4);
-- this one is ok
select a,b from buggy where a = 2 intersect select a,b from buggy
where a = 2;
-- this one gets an empty row
select a,b from buggy where a = 2 intersect select a,b from buggy
where a != 3;
-- this also
select a,b from buggy intersect select a,b from buggy where a = 3;
...
