levertond@googlemail.com writes:
> The following query fails with the message "JOIN qualification cannot refer
> to other relations":
> SELECT *
> FROM (SELECT 1 AS x) x
> CROSS JOIN (SELECT 1 AS y) y
> LEFT JOIN LATERAL (
> SELECT *
> FROM (SELECT 1 AS z) z
> WHERE z.z = x.x
> ) z ON z.z = y.y;
> I don't see why this shouldn't be legal, but if it isn't it should at least
> give a less vague error message.
Yeah, that query looks legal to me too. It's tripping over a planner bug,
and the error report is from an internal consistency check, which explains
its not-too-user-friendly nature. Will fix, thanks for the report!
regards, tom lane