Re: Eager aggregation, take 3

Richard Guo <guofenglinux(at)gmail(dot)com> 于2024年8月21日周三 15:11写道：

> On Fri, Aug 16, 2024 at 4:14 PM Richard Guo <guofenglinux(at)gmail(dot)com>
> wrote:
> > I had a self-review of this patchset and made some refactoring,
> > especially to the function that creates the RelAggInfo structure for a
> > given relation. While there were no major changes, the code should
> > now be simpler.
>
> I found a bug in v10 patchset: when we generate the GROUP BY clauses
> for the partial aggregation that is pushed down to a non-aggregated
> relation, we may produce a clause with a tleSortGroupRef that
> duplicates one already present in the query's groupClause, which would
> cause problems.
>
> Attached is the updated version of the patchset that fixes this bug
> and includes further code refactoring.
>

Rectenly, I do some benchmark tests, mainly on tpch and tpcds.
tpch tests have no plan diff, so I do not continue to test on tpch.
tpcds(10GB) tests have 22 plan diff as below:
4.sql, 5.sql, 8.sql,11.sql,19.sql,23.sql,31.sql,
33.sql,39.sql,45.sql,46.sql,47.sql,53.sql,
56.sql,57.sql,60.sql,63.sql,68.sql,74.sql,77.sql,80.sql,89.sql

I haven't look all of them. I just pick few simple plan test(e.g. 19.sql,
45.sql).
For example, 19.sql, eager agg pushdown doesn't get large gain, but a little
performance regress.

I will continue to do benchmark on this feature.

[1] https://github.com/tenderwg/eager_agg

--
Tender Wang