=?utf-8?q?PG_Bug_reporting_form?= <noreply(at)postgresql(dot)org> writes:
> This error can be reproduced easily as follows
> postgres=# SELECT count(*) OVER (GROUPS 1 PRECEDING) FROM (VALUES (1),
> (2), (2)) t(v);
> ERROR: unexpected end of tuplestore
In an assert-enabled build I get an assert failure from this. I think
this is the same problem Masahiko Sawada noted in
https://www.postgresql.org/message-id/CAD21AoDrWqycq-w_+Bx1cjc+YUhZ11XTj9rfxNiNDojjBx8Fjw@mail.gmail.com
and as in that thread, I think what we really should be doing here is
giving a parse error. What would you expect GROUPS mode to do without
an ORDER BY to define the grouping?
regards, tom lane