Re: PK vs Unique index

In article <m31ygqhxag.fsf_at_colorado.arsdigita.de>, Dirk says...
>
>> A primary key is much more then a unique index (doesn't even have to use a
>> unique index actually)...
>
>Could you explain this in a little more detail please?

Starting with 8.0 -- when we added deferrable constraints -- you can use a unique or non-unique index with a primary key.

If the constraint is deferrable -- a non-unique index must be used. If the constraint is non-deferrable -- either type may be used.

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