Hey everyone, As you know, Postgres currently supports SQL:1999 recursive common table expressions, using WITH RECURSIVE. However, Postgres does not allow more than one recursive self-reference in the recursive term. This restriction seems to be unnecessary.
In this mail, I'd like to propose a patch that removes this restriction, and
therefore allows the use of multiple self-references in the recursive term.
After the patch:
WITH RECURSIVE t(n) AS (
VALUES(1)
UNION ALL
SELECT t.n+f.n
FROM t, t AS f
WHERE t.n < 100
) SELECT * FROM t;
n
-----
1
2
4
8
16
32
64
128
(8 rows)
This feature deviates only slightly from the current WITH RECURSIVE, and
requires very little changes (~10 loc). Any thoughts on this?
--
Denis Hirn
0001-Allow-multiple-recursive-self-references.patch
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