Re: EXPLAIN VERBOSE with parallel Aggregate

On Tue, Apr 26, 2016 at 6:44 PM, David Rowley
<david(dot)rowley(at)2ndquadrant(dot)com> wrote:
> On 27 April 2016 at 08:46, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> My proposed fix for this issue is attached. Review is welcome;
>> otherwise, I'll just commit this. The output looks like what I
>> suggested upthread:
>
> + if (!aggref->aggpartial)
> + elog(ERROR, "referenced Aggref is not partial");
>
> I think this is overly restrictive; ruleutils seems a bit out of line
> here to say that plans can't have > 1 combine aggregate node.
>
> When coding the combine aggs stuff I had test code to inject
> additional combine paths to make sure everything worked as expected.
> It did, but it won't if you add these two lines. I'd say just remove
> them.
>
> If you apply the attached and execute;
>
> create table t1 (num int not null);
> insert into t1 select generate_series(1,2000000);
>
> explain verbose select avg(num) from t1;
>
> You'll get;
>
> ERROR: referenced Aggref is not partial

In this test patch, should aggpath be using partial_grouping_target
rather than target? I feel like we need to use
partial_grouping_target unless finalizeAggs is true.

--
Robert Haas
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