Re: multiset patch review

On Wed, Jan 12, 2011 at 20:18, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
> there is one issue - probably useless checking a type equality in
> function check_comparable and check_concatinatable, because when your
> function is registrated with arguments (anyarray, anyarray), then is
> guaranteed so type of array1 is same as type of array2, and then you
> don't need to check.

It's true for almost all cases, but we have "anyarray" columns in
pg_statistic.stavaluesN. When we pass them to those array functions,
element types of two anyarrays could be different.
I guess they are protections only for them.

=# SELECT A.stavalues1 SUBMULTISET OF B.stavalues1
FROM pg_statistic A, pg_statistic B
WHERE A.stakind1 = 2 AND B.stakind1 = 2;
ERROR: cannot compare incompatible arrays
DETAIL: Arrays with element types name and oid[] are not compatible
for comparison.

--
Itagaki Takahiro