On 10 January 2018 at 09:26, Tom Lane wrote:
> 1. Once you don't have all the tlist items shown in DISTINCT, it really is
> more like DISTINCT ON, seems like. I am not sure it's a good idea to set
> hasDistinctOn, because that engages some planner behaviors we probably
> don't want, but I'm also
On 2 March 2018 at 09:51, Andres Freund wrote:
> This patch has been waiting on author since 2018-01-09, the next & last
> CF has started. I'm inclined to mark this as returned with feedback.
I'm planning on making the required changes at the weekend.
--
David Rowley http://
Hi,
On 2018-01-10 11:12:17 +1300, David Rowley wrote:
> I'll do some more analysis on places that distinctClause is being used
> to check what's safe.
This patch has been waiting on author since 2018-01-09, the next & last
CF has started. I'm inclined to mark this as returned with feedback.
Gree
Hi Tom,
Thanks for looking at this.
On 10 January 2018 at 09:26, Tom Lane wrote:
> This is a cute idea, but I'm troubled by a couple of points:
>
> 1. Once you don't have all the tlist items shown in DISTINCT, it really is
> more like DISTINCT ON, seems like. I am not sure it's a good idea to s
David Rowley writes:
> [ remove_useless_distinct_clauses_v2.patch ]
This is a cute idea, but I'm troubled by a couple of points:
1. Once you don't have all the tlist items shown in DISTINCT, it really is
more like DISTINCT ON, seems like. I am not sure it's a good idea to set
hasDistinctOn, bec
On 6 January 2018 at 23:08, David Rowley wrote:
>> I think remove_functionally_dependant_groupclauses should have a more
>> generic name, like remove_functionally_dependant_clauses.
>
> It's been a while since I looked at this. I remember thinking
> something similar at the time but I must have no
Hi Jeff,
Thanks for looking at the patch.
On 6 January 2018 at 10:34, Jeff Janes wrote:
> Couldn't the Unique node be removed entirely? If k is a primary key, you
> can't have duplicates in need of removal.
It probably could be, if there were no joins, but any join could
duplicate those rows,
On Mon, Nov 6, 2017 at 1:16 AM, David Rowley
wrote:
> In [1] we made a change to process the GROUP BY clause to remove any
> group by items that are functionally dependent on some other GROUP BY
> items.
>
> This really just checks if a table's PK columns are entirely present
> in the GROUP BY cl
