Janning Vygen <vygen(at)gmx(dot)de> wrote:
>
[snip]
>
> Thanks to Tom and Peter for your answers. I will design my table without a
> primary key and use my unique index instead of a primary key. As this unique
> key is the same as a primary key i dont see the reason why postgresql
> should't extend the specs and allow functional primary key indizes.
Because, as Tom Lane wrote: "The SQL spec says that primary keys are
columns or lists of columns." Unlike some other SQL RDBMs, PostgreSQL
at least *tries* (mostly) to be SQL standards compliant.
Jim