Re: Unexpected results when using GROUP BY GROUPING SETS and bind variables

Aner Perez <aner(dot)perez+pgsql-general(at)gmail(dot)com> writes:
> Or if using indexed path elements in the GROUP BY is the issue and I should
> put the array indexing in a subselect and do the aggregation in the outer
> select. Like this:

> -- Safer Subselect Version --
> SELECT level1, level2, level3, level4, sum(value)
> FROM (
> SELECT path[1] as level1, path[2] as level2, path[3] as level3, path[4]
> as level4, value
> FROM bind_group_by
> ) AS expanded
> GROUP BY GROUPING SETS (
> (level1, level2, level3, level4),
> (level1, level2, level3),
> (level1, level2),
> (level1),
> ()
> )
> ORDER BY 1, 2, 3, 4;

Yeah, that one looks a lot safer from here. There's no question about
which expressions are supposed to match what. It should end up with
the same plan, too.

regards, tom lane