On Wed, Jan 07, 2015 at 05:18:58PM -0800, Peter Geoghegan wrote:
> On Wed, Jan 7, 2015 at 5:16 PM, David Fetter <david@fetter.org> wrote:
> > There's precedent. Unique constraints, for example.
>
> I don't see that as any kind of precedent.
In the part you sliced off, Stephen described a situation where the
contents of a database either do or don't cause a query to violate a
constraint. Uniqueness constraints are one example of this.
CREATE TABLE foo(id INTEGER PRIMARY KEY);
INSERT INTO foo(id) VALUES(1); /* Works the first time */
INSERT INTO foo(id) VALUES(1); /* Fails the next time */
Same database, same constraints, different outcome.
Cheers,
David.
--
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
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