Обсуждение: Reference on partial data

Hi,
is it possible to create reference constraint only on defined subset of 
data?

Reference can be defined on column which has unique constraint. It is 
also possible to create partial unique index. So it should by possible 
to reference this column. But postgres can not see this constraint and 
raises: ERROR:  there is no unique constraint matching given keys for 
referenced table

Any ideas ???

I dont feel my self to rewrite builtin trigger function which ensures 
reference integrity.

mito wrote:
> Hi,
> is it possible to create reference constraint only on defined subset 
> of data?
>
> Reference can be defined on column which has unique constraint. It is 
> also possible to create partial unique index. So it should by possible 
> to reference this column. But postgres can not see this constraint and 
> raises: ERROR:  there is no unique constraint matching given keys for 
> referenced table
>
> Any ideas ???
>
> I dont feel my self to rewrite builtin trigger function which ensures 
> reference integrity.
>

No, it's not.

This looks like a usage question, which doesn't belong on -hackers. 
Please ask such questions on pgsql-general.

cheers

andrew