Re: EXPLAIN VERBOSE with parallel Aggregate

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

--
David Rowley http://www.2ndQuadrant.com/
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