Re: PL/pgSQL EXECUTE '..' USING with unknown

Andrew Dunstan <andrew@dunslane.net> writes:
> On 08/05/2010 05:11 PM, Tom Lane wrote:
>> This example doesn't seem terribly compelling.  Why would you bother
>> using USING with constants?

> In a more complex example you might use $1 in more than one place in the 
> query.

Well, that's better than no justification, but it's still pretty weak.
A bigger problem is that doing anything like this will require reversing
the logical path of causation in EXECUTE USING.  Right now, we evaluate
the USING expressions first, and then their types feed forward into
parsing the EXECUTE string.  What Heikki is suggesting requires
reversing that, at least to some extent.  I'm not convinced it's
possible without breaking other cases that are more important.
        regards, tom lane