Re: Setting a pre-existing index as a primary key - Mailing list pgsql-hackers

From Jonah H. Harris
Subject Re: Setting a pre-existing index as a primary key
Date
Msg-id 36e682920804082003m5d3fba19y3d500944cd1cbeda@mail.gmail.com
Whole thread Raw
In response to Re: Setting a pre-existing index as a primary key  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Setting a pre-existing index as a primary key  ("Jaime Casanova" <systemguards@gmail.com>)
List pgsql-hackers
On Tue, Apr 8, 2008 at 9:04 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "Jonah H. Harris" <jonah.harris@gmail.com> writes:
>  > I've run into a couple cases now where it would be helpful to easily
>  > assign an already-existing unique index as a primary key.
>
>  You need to present a more convincing use-case than this unsupported
>  assertion.  There's hardly any effective difference between a unique
>  index + NOT NULL constraints and a declared primary key ... so what
>  did you really need it for?

Agreed, functionally there's not much of a difference.  It's more of a
matter of proper design identifying a primary key.

>  > 1. Verify that the index named is a unique index
>
>  ... and not partial, and not on expressions, and not invalid, and not
>  using non-default opclasses (which might have a surprising definition of
>  "equal"), and not already owned by a constraint ... not to mention that
>  it'd better be an index on the named table, which among other things
>  removes the need for a schema specification on the index name.

Of course.

-- 
Jonah H. Harris, Sr. Software Architect | phone: 732.331.1324
EnterpriseDB Corporation | fax: 732.331.1301
499 Thornall Street, 2nd Floor | jonah.harris@enterprisedb.com
Edison, NJ 08837 | http://www.enterprisedb.com/


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