We have found a possible bug in 7.3.1. It seems that using CROSS JOIN and doing plain Cartesian product, listing to tables in the from clause, gives different results. According to the documentation this should be equivalent. The following example should explain the problem:
CREATE TABLE a (a1 text, a2 text); CREATE TABLE b (b1 text, b2 text); CREATE TABLE c (a1 text, b1 text, c1 text);
INSERT INTO a VALUES('a1', 'a2');
INSERT INTO b VALUES('b1', 'b2');
INSERT INTO c VALUES('a3', 'b1', 'c1');SELECT * FROM a,b NATURAL JOIN c; a1 | a2 | b1 | b2 | a1 | c1 ----+----+----+----+----+---- a1 | a2 | b1 | b2 | a3 | c1 (1 row)
SELECT * FROM a CROSS JOIN b NATURAL JOIN c; a1 | b1 | a2 | b2 | c1 ----+----+----+----+---- (0 rows)
These two example queries should give the same result. In the first query, it seems like itâs doing the natural join between b and c, and then does the Cartesian product on that result with a. On the second query, it does as we assume it should, namely does the Cartesian product first.
Is this the correct behavior?
Regards
Ãsmund
-- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to [EMAIL PROTECTED] so that your
message can get through to the mailing list cleanly
