Re: rules: evaluate inputs in advance

On Fri, 2006-05-12 at 15:57 +0200, Martijn van Oosterhout wrote:
> It's a known problem. It's also one of the reasons why triggers are
> recommended over rules. And it's not desirable behaviour.

Well, triggers cannot be used to create writeable views, can they?

> There have been discussions about the problems

Do you have some pointers here? I did not find relevant discussions in
the archives (of gmane.org)

> Yet no-one has come up with an
> alternative that covers the current uses...

As far as I know, the rewriter simply copies plan tree nodes. I thought
about inserting an 'evaluate-only-once' node which is linked from all
rules and points to the expression to evaluate (instead of copying the
complete explession and evaluating it several times in the executor).

Regards

Markus