This bug appears to still exist in 7.0:
test=> create table test (zone int4, net cidr, unique(zone, net));
NOTICE: CREATE TABLE/UNIQUE will create implicit index 'test_zone_key'
for table 'test'
CREATE
test=> insert into test (zone, net) values (1, '1.2.3/24');
INSERT 22157 1
test=> insert into test (zone, net) values (1, '2.3.4/24');
INSERT 22158 1
test=> select * from test;
zone | net
------+----------
1 | 1.2.3/24
1 | 2.3.4/24
(2 rows)
test=> insert into test (zone, net) values (1, '2.3.4/24');
INSERT 22159 1
test=>
> Solaris 2.6/sparc; postgres 6.5.1
>
> dns=> create table test (zone int4, net cidr, unique(zone, net));
> NOTICE: CREATE TABLE/UNIQUE will create implicit index 'test_zone_key' for table 'test'
> CREATE
> dns=> insert into test (zone, net) values (1, '1.2.3/24');
> INSERT 21750 1
> dns=> insert into test (zone, net) values (1, '2.3.4/24');
> INSERT 21751 1
> dns=> insert into test (zone, net) values (1, '1.2.3/24');
> INSERT 21752 1
> dns=> insert into test (zone, net) values (1, '2.3.4/24');
> ERROR: Cannot insert a duplicate key into a unique index
> dns=> select * from test;
> zone|net
> - ----+--------
> 1|1.2.3/24
> 1|2.3.4/24
> 1|1.2.3/24
> (3 rows)
>
>
> Once a unique error is reported, uniqueness seems to be maintained.
> Also, if you enter 4 values, then try a duplicate, it all works.
>
> The threshold seems to be 3.
>
> A select before the duplicate add also seems to fix it.
>
> ~f
>
>
>
> ************
>
>
--
Bruce Momjian | http://www.op.net/~candle
pgman@candle.pha.pa.us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
