I have added a link to this from the exiting TODO item:
Improve handling of NULLs in arrays
* BUG #4509: array_cat's null behaviour is inconsistent
* http://archives.postgresql.org/pgsql-hackers/2010-11/msg01040.php
--
There might be inconsistency in overlap operators for array
types ( <@, @>, and && ) when the argument arrays contain NULLs.
- SELECT 2 = ANY (ARRAY[1, NULL]) => NULL
- SELECT ARRAY[2] <@ ARRAY[1, NULL] => false
NULL means "unknown" in definition, so should it return NULL
rather than false?
I
