The following bug has been logged on the website: Bug reference: 6669 Logged by: jose soares Email address: jose.soa...@sferacarta.com PostgreSQL version: 8.4.8 Operating system: x86_64-pc-linux-gnu, debian Description:
Hi, I think I have found an error in pg or at least inconsistency, take a look at this. I created an unique index on two columns and pg let me enter repeated values as NULLs (unknown value), When I ask pg to tell me if there are repetitions n this index (with group by), the inconsistency becomes apparent. # create table test(id int, data date, code int); CREATE TABLE # create UNIQUE index unica on test(data,code); CREATE INDEX # \d test Table "public.test" Column | Type | Modifiers --------+---------+----------- id | integer | data | date | code | integer | Indexes: "unica" UNIQUE, btree (data, code) # insert into test values(1,current_date); INSERT 0 1 # insert into test values(2,current_date); INSERT 0 1 # insert into test values(3,current_date); INSERT 0 1 sicer_forli=# select current_date,code, count(*) from test group by 1,2; date | code | count ------------+------+------- 31-05-2012 | | 3 (1 row) ps: Oracle don't allows to insert two NULLs in such column. I don't know which of them is SQL Standard, but in this case oracle is not inconsistent. -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs