On Mon, 5 Feb 2024 at 14:42, Richard Guo wrote:
>
>
> On Fri, Feb 2, 2024 at 7:36 PM David Rowley wrote:
>> I think we should just make it work the same way as
>> create_grouping_paths(), where grouping_target is passed as a
>> parameter.
>>
>> I've done it that way in the attached.
>
>
> The cha
On Fri, Feb 2, 2024 at 7:36 PM David Rowley wrote:
> Now for the other stuff you had. I didn't really like this part:
>
> + /*
> + * Set target for partial_distinct_rel as generate_useful_gather_paths
> + * requires that the input rel has a valid reltarget.
> + */
> + partial_distinct_rel->relt
On Fri, Feb 2, 2024 at 6:39 PM David Rowley wrote:
> So the gains increase with more parallel workers due to pushing more
> work to the worker. Amdahl's law approves of this.
>
> I'll push the patch shortly.
Thanks for the detailed testing and pushing the patch!
Thanks
Richard
On Fri, 2 Feb 2024 at 23:39, David Rowley wrote:
> I'll push the patch shortly.
I've pushed the partial path sort part.
Now for the other stuff you had. I didn't really like this part:
+ /*
+ * Set target for partial_distinct_rel as generate_useful_gather_paths
+ * requires that the input rel
On Fri, 2 Feb 2024 at 20:47, Richard Guo wrote:
>
>
> On Fri, Feb 2, 2024 at 11:26 AM David Rowley wrote:
>>
>> In light of this, do you still think it's worthwhile making this change?
>>
>> For me, I think all it's going to result in is extra planner work
>> without any performance gains.
>
>
>
On Fri, Feb 2, 2024 at 11:26 AM David Rowley wrote:
> In light of this, do you still think it's worthwhile making this change?
>
> For me, I think all it's going to result in is extra planner work
> without any performance gains.
Hmm, with the query below, I can see that the new plan is cheaper
On Wed, 27 Dec 2023 at 00:23, Richard Guo wrote:
> -- on master
> EXPLAIN (costs off)
> SELECT DISTINCT four FROM tenk1;
> QUERY PLAN
>
> Unique
>-> Sort
> Sort Key: four
> -> Gather
>
