Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi> writes:
> On 2010-09-14 10:51 PM, Tom Lane wrote:
>> My recollection is that whether a CTE is marked RECURSIVE or not affects
>> its scope of visibility, so that confusing the two cases can result in
>> flat-out incorrect parser behavior.
> The worst I can think of is:
> CREATE TABLE foo(a int);
> WITH t AS (SELECT * FROM foo)
> INSERT INTO bar
> WITH RECURSIVE foo (SELECT 1 AS a)
> SELECT * FROM t;
> t will actually be populated with the results of the CTE, not the table foo.
> I don't think this is a huge problem in real life, but if someone thinks
> otherwise, I think we could just error out if the lists have a different
> RECURSIVE definition.
Wrong is wrong. Doesn't matter whether it's "a huge problem in real life".
Why is it so difficult to do this correctly?
regards, tom lane