Re: Proposing WITH ITERATIVE

On 2020-04-29 07:09, Fabien COELHO wrote:
> I'm wondering about how to use such a feature in the context of WITH query
> with several queries having different behaviors. Currently "WITH"
> introduces a named-query (like a view), "WITH RECURSIVE" introduces a mix
> of recursive and named queries, pg really sees whether each one is
> recursive or not, and "RECURSIVE" is required but could just be guessed.

Yeah the RECURSIVE vs ITERATIVE is a bit of a red herring here.  As you 
say, the RECURSIVE keyword doesn't specify the processing but marks the 
fact that the specification of the query is recursive.

I think a syntax that would fit better within the existing framework 
would be something like

WITH RECURSIVE t AS (
     SELECT base case
   REPLACE ALL  -- instead of UNION ALL
     SELECT recursive case
)

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
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