Can anyone explain the ERROR below? Is this a bug or a feature?
This is 7.0.2.
test=# select (1,2,3) = (1,2,3);
?column?
----------
t
(1 row)
test=# select (1,2,3) = (1,2,9);
?column?
----------
f
(1 row)
test=# select (1,2,3) = (1,2,null);
?column?
----------
(1 row)
test=# select (1,2,null) = (1,2,null);
ERROR: Unable to identify an operator '=' for types 'unknown' and 'unknown'
You will have to retype this query using an explicit cast
--
Tatsuo Ishii