PG Bug reporting form <noreply@postgresql.org> writes:
> [ unreadable example ]
This can be boiled down to
CREATE TEMP TABLE v0 ( v2 int );
INSERT INTO v0 VALUES (1);
SELECT (
SELECT
MODE ( ) WITHIN GROUP ( ORDER BY v2 )
FILTER ( WHERE MODE ( ) WITHIN GROUP ( ORDER BY v2 > 0 ) )
)
FROM v0;
It seems fairly clear to me that this ought to be rejected as invalid,
because we don't allow aggregates within the arguments of aggregates.
That does happen without the sub-select:
regression=# SELECT
regression-# MODE ( ) WITHIN GROUP ( ORDER BY v2 )
regression-# FILTER ( WHERE MODE ( ) WITHIN GROUP ( ORDER BY v2 > 0 ) )
regression-# FROM v0;
ERROR: aggregate functions are not allowed in FILTER
LINE 3: FILTER ( WHERE MODE ( ) WITHIN GROUP ( ORDER BY v2 > 0 )...
^
So somehow the fact that outer references are involved is misleading that
error check. I've not traced it further than that.
regards, tom lane
