Dennis Haney <[EMAIL PROTECTED]> writes: > Consider this example: > SELECT * FROM a,b WHERE a.id = b.id AND (a.id) IN (SELECT c.id FROM c) > the possible execution trees are {{a,b}, {c}}, {{a,c},{b}} and the code > seems to also permit {{b,c},{a}}.
No, it does not --- as you say, that would give wrong answers. That case is eliminated by the tests following this comment: * JOIN_IN technique will work if outerrel includes LHS and * innerrel is exactly RHS; conversely JOIN_REVERSE_IN handles * RHS/LHS. * * JOIN_UNIQUE_OUTER will work if outerrel is exactly RHS; * conversely JOIN_UNIQUE_INNER will work if innerrel is * exactly RHS. Joining {b,c} to {a} does not meet any of those four allowed cases. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]