>>>>> "Tatsuo" == Tatsuo Ishii <[EMAIL PROTECTED]> writes:
>> This behaviour is clearly intentional, since the entire mechanism of >> estate-> es_disallow_tuplestore exists for no other reason, but it >> seems to me to be clearly wrong. What is the justification for it? Tatsuo> Yes, this is due to prevent infinit recursion caused by Tatsuo> following case for example. [...] Tatsuo> WITH RECURSIVE x AS ( Tatsuo> SELECT * FROM test WHERE a = 'aaa' Tatsuo> UNION ALL Tatsuo> SELECT test.* FROM x LEFT JOIN test on test.a = x.b Tatsuo> ) SELECT * FROM x; Tatsuo> Now we think that we were wrong. This type of query should Tatsuo> run into infinit recursion and it's user's responsibility Tatsuo> that he does not make such a query. I agree. Tatsuo> Another idea would be prohibiting *any* outer joins in the Tatsuo> recursive term (DB2 style), but this may be overkill. There are legitimate cases for wanting to do a left join in the recursion - for example, to use the content of another table to prune the tree where matching records exist (consider the standard bill-of-materials example with the addition of another table listing components already in stock). -- Andrew (irc:RhodiumToad) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
