Re: Status of Hierarchical Queries

"Gavin Sherry" <swm(at)alcove(dot)com(dot)au> writes:

> The WITH support seems okay. I guess I'd thought it might be represented
> different internally (not a sub query) but the approach Greg has taken is
> probably more straight forward (in that you get a lot of proven code for
> free). It should work fine for recursive queries too, if you just re-seed
> the param keys for every scan of the 'sub-query'.

I don't think it works for recursive queries. Since you can't have the same
executor plan in motion for two different sets of parameters simultaneously.
That's why I was talking about a Memoize node.

It is sufficient for the non-recursive case which might make it worthwhile
putting it in 8.3. But even there user's expectations are probably that the
reason they're writing it as a cte is precisely to avoid duplicate execution.

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com