Reece Hart wrote:
> On Tue, May 20, 2008 at 02:25:15PM -0400, Decibel! wrote:
> > I need to add a field to a fairly large table. In the same alter statement
> > I'd like to add a FK constraint on that new field. Is there any way to
> > avoid the check of the table that the database is doing right now? The
> > check is pointless because the newly added field is nothing but NULLs.
> >
> I don't see the problem. FK constraints don't fire on NULL values. I
> think you might be imagining that a problem exists when it doesn't.
The problem is that it does a table scan only to find that all values
are NULL, which is pretty pointless.
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Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.