Eric Miller writes:
> With 8.4RC1, I get the following error with the SQL below.
> ERROR: failed to find conversion function from unknown to character varying
Every PG version since 7.1 complains about that query, because it's
underspecified. Cast the NULL to something specific in the sub-SELECT
With 8.4RC1, I get the following error with the SQL below.
ERROR: failed to find conversion function from unknown to character varying
SQL state: XX000
SELECT 0 AS "C1", cast('a' as varchar) AS "C2"
UNION ALL
SELECT 1 AS "C1", "X"."XX" AS "C2"
FROM ( SELECT NULL AS "XX" ) AS "X"
WHERE TRUE = F
