David E. Wheeler wrote:
> This code:
>
> CREATE OR REPLACE FUNCTION foo() returns boolean as $$
> DECLARE
> have_rec record;
> want_rec record;
> BEGIN
> have_rec := row(1, 2);
> want_rec := row(3, 5);
> RETURN have_rec IS DISTINCT FROM want_rec;
> END;
> $$ language plpgsql;
>
> SELECT ROW(1, 2) IS DISTINCT FROM ROW(3, 5);
>
> SELECT foo();
> DROP FUNCTION foo();
>
> Works as expected on 8.4, outputting:
>
[...]
>
> On 8.3, however, the row comparisons in the SQL statement works, but
> fails in the PL/pgSQL function, with this output:
>
> ?column?
> ----------
> t
> (1 row)
>
> psql:huh.sql:14: ERROR: operator does not exist: record = record
> LINE 1: SELECT $1 IS DISTINCT FROM $2
> ^
> HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
> QUERY: SELECT $1 IS DISTINCT FROM $2
> CONTEXT: PL/pgSQL function "foo" line 7 at RETURN
>
>
> Is this a known issue in 8.3? If so, is there a known workaround?
The change is probably here:
http://archives.postgresql.org/pgsql-committers/2008-10/msg00110.php
So I think it is safe to argue that this is not a bug in 8.3, but an improvement in 8.4.
Yours,
Laurenz Albe