On Wed, Oct 08, 2008 at 01:36:37PM +0200, A. Kretschmer wrote:
> test=*# select * from dup;
> a | b
> ---+---
> 1 | 1
> 1 | 2
> 2 | 1
> 1 | 1
> 3 | 3
> 3 | 3
> (6 rows)
>
> test=*# select * from dup where (ctid,a,b) not in (select distinct on (a,b) ctid,* from dup);
> a | b
> ---+---
> 1 | 1
> 3 | 3
> (2 rows)
another approach:
select a,b from dup group by a,b having count(*) > 1;
depesz
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