Обсуждение: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

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Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
tender wang
Дата:
Hi all,

   I recently run benchmark[1] on master, but I found performance problem as below:

explain analyze select
  subq_0.c0 as c0,
  subq_0.c1 as c1,
  subq_0.c2 as c2
from
  (select
        ref_0.l_shipmode as c0,
        sample_0.l_orderkey as c1,
        sample_0.l_quantity as c2,
        ref_0.l_orderkey as c3,
        sample_0.l_shipmode as c5,
        ref_0.l_shipinstruct as c6
      from
        public.lineitem as ref_0
          left join public.lineitem as sample_0
          on ((select p_partkey from public.part order by p_partkey limit 1)
                 is not NULL)
      where sample_0.l_orderkey is NULL) as subq_0
where subq_0.c5 is NULL
limit 1;
                                                               QUERY PLAN                                                                
-----------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=78.00..45267050.75 rows=1 width=27) (actual time=299695.097..299695.099 rows=0 loops=1)
   InitPlan 1 (returns $0)
     ->  Limit  (cost=78.00..78.00 rows=1 width=8) (actual time=0.651..0.652 rows=1 loops=1)
           ->  Sort  (cost=78.00..83.00 rows=2000 width=8) (actual time=0.650..0.651 rows=1 loops=1)
                 Sort Key: part.p_partkey
                 Sort Method: top-N heapsort  Memory: 25kB
                 ->  Seq Scan on part  (cost=0.00..68.00 rows=2000 width=8) (actual time=0.013..0.428 rows=2000 loops=1)
   ->  Nested Loop Left Join  (cost=0.00..45266972.75 rows=1 width=27) (actual time=299695.096..299695.096 rows=0 loops=1)
         Join Filter: ($0 IS NOT NULL)
         Filter: ((sample_0.l_orderkey IS NULL) AND (sample_0.l_shipmode IS NULL))
         Rows Removed by Filter: 3621030625
         ->  Seq Scan on lineitem ref_0  (cost=0.00..1969.75 rows=60175 width=11) (actual time=0.026..6.225 rows=60175 loops=1)
         ->  Materialize  (cost=0.00..2270.62 rows=60175 width=27) (actual time=0.000..2.554 rows=60175 loops=60175)
               ->  Seq Scan on lineitem sample_0  (cost=0.00..1969.75 rows=60175 width=27) (actual time=0.004..8.169 rows=60175 loops=1)
 Planning Time: 0.172 ms
 Execution Time: 299695.501 ms
(16 rows)

After I set enable_material to off, the same query run faster, as below:
set enable_material = off;
explain analyze  select
  subq_0.c0 as c0,
  subq_0.c1 as c1,
  subq_0.c2 as c2
from
  (select
        ref_0.l_shipmode as c0,
        sample_0.l_orderkey as c1,
        sample_0.l_quantity as c2,
        ref_0.l_orderkey as c3,
        sample_0.l_shipmode as c5,
        ref_0.l_shipinstruct as c6
      from
        public.lineitem as ref_0
          left join public.lineitem as sample_0
          on ((select p_partkey from public.part order by p_partkey limit 1)
                 is not NULL)
      where sample_0.l_orderkey is NULL) as subq_0
where subq_0.c5 is NULL
limit 1;
                                                                  QUERY PLAN                                                                  
-----------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=1078.00..91026185.57 rows=1 width=27) (actual time=192669.605..192670.425 rows=0 loops=1)
   InitPlan 1 (returns $0)
     ->  Limit  (cost=78.00..78.00 rows=1 width=8) (actual time=0.662..0.663 rows=1 loops=1)
           ->  Sort  (cost=78.00..83.00 rows=2000 width=8) (actual time=0.661..0.662 rows=1 loops=1)
                 Sort Key: part.p_partkey
                 Sort Method: top-N heapsort  Memory: 25kB
                 ->  Seq Scan on part  (cost=0.00..68.00 rows=2000 width=8) (actual time=0.017..0.430 rows=2000 loops=1)
   ->  Gather  (cost=1000.00..91026107.57 rows=1 width=27) (actual time=192669.604..192670.422 rows=0 loops=1)
         Workers Planned: 1
         Params Evaluated: $0
         Workers Launched: 1
         ->  Nested Loop Left Join  (cost=0.00..91025107.47 rows=1 width=27) (actual time=192588.143..192588.144 rows=0 loops=2)
               Join Filter: ($0 IS NOT NULL)
               Filter: ((sample_0.l_orderkey IS NULL) AND (sample_0.l_shipmode IS NULL))
               Rows Removed by Filter: 1810515312
               ->  Parallel Seq Scan on lineitem ref_0  (cost=0.00..1721.97 rows=35397 width=11) (actual time=0.007..3.797 rows=30088 loops=2)
               ->  Seq Scan on lineitem sample_0  (cost=0.00..1969.75 rows=60175 width=27) (actual time=0.000..2.637 rows=60175 loops=60175)
 Planning Time: 0.174 ms
 Execution Time: 192670.458 ms
(19 rows)

I debug the code and find consider_parallel_nestloop() doesn't consider materialized form of the cheapest inner path.
When enable_material = true,  we can see Material path won in first plan, but Parallel Seq Scan node doesn't add as outer path, which because
in try_partial_nestloop_path() , the cost of nestloop wat computed using seq scan path not material path. 

[1] include test table schema and data, you can repeat above problem.

I try fix this problem in attached patch, and I found pg12.12 also had this issue. Please review my patch, thanks! 

Вложения

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
tender wang
Дата:
After using patch, the result as below :
                                                                   QUERY PLAN                                                                  
------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=1078.00..26630101.20 rows=1 width=27) (actual time=160571.005..160571.105 rows=0 loops=1)
   InitPlan 1 (returns $0)
     ->  Limit  (cost=78.00..78.00 rows=1 width=8) (actual time=1.065..1.066 rows=1 loops=1)
           ->  Sort  (cost=78.00..83.00 rows=2000 width=8) (actual time=1.064..1.065 rows=1 loops=1)
                 Sort Key: part.p_partkey
                 Sort Method: top-N heapsort  Memory: 25kB
                 ->  Seq Scan on part  (cost=0.00..68.00 rows=2000 width=8) (actual time=0.046..0.830 rows=2000 loops=1)
   ->  Gather  (cost=1000.00..26630023.20 rows=1 width=27) (actual time=160571.003..160571.102 rows=0 loops=1)
         Workers Planned: 1
         Params Evaluated: $0
         Workers Launched: 1
         ->  Nested Loop Left Join  (cost=0.00..26629023.10 rows=1 width=27) (actual time=160549.257..160549.258 rows=0 loops=2)
               Join Filter: ($0 IS NOT NULL)
               Filter: ((sample_0.l_orderkey IS NULL) AND (sample_0.l_shipmode IS NULL))
               Rows Removed by Filter: 1810515312
               ->  Parallel Seq Scan on lineitem ref_0  (cost=0.00..1721.97 rows=35397 width=11) (actual time=0.010..3.393 rows=30088 loops=2)
               ->  Materialize  (cost=0.00..2270.62 rows=60175 width=27) (actual time=0.000..2.839 rows=60175 loops=60175)
                     ->  Seq Scan on lineitem sample_0  (cost=0.00..1969.75 rows=60175 width=27) (actual time=0.008..11.381 rows=60175 loops=2)
 Planning Time: 0.174 ms
 Execution Time: 160571.476 ms
(20 rows)

tender wang <tndrwang@gmail.com> 于2023年9月5日周二 16:52写道：
Hi all,

   I recently run benchmark[1] on master, but I found performance problem as below:

explain analyze select
  subq_0.c0 as c0,
  subq_0.c1 as c1,
  subq_0.c2 as c2
from
  (select
        ref_0.l_shipmode as c0,
        sample_0.l_orderkey as c1,
        sample_0.l_quantity as c2,
        ref_0.l_orderkey as c3,
        sample_0.l_shipmode as c5,
        ref_0.l_shipinstruct as c6
      from
        public.lineitem as ref_0
          left join public.lineitem as sample_0
          on ((select p_partkey from public.part order by p_partkey limit 1)
                 is not NULL)
      where sample_0.l_orderkey is NULL) as subq_0
where subq_0.c5 is NULL
limit 1;
                                                               QUERY PLAN                                                                
-----------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=78.00..45267050.75 rows=1 width=27) (actual time=299695.097..299695.099 rows=0 loops=1)
   InitPlan 1 (returns $0)
     ->  Limit  (cost=78.00..78.00 rows=1 width=8) (actual time=0.651..0.652 rows=1 loops=1)
           ->  Sort  (cost=78.00..83.00 rows=2000 width=8) (actual time=0.650..0.651 rows=1 loops=1)
                 Sort Key: part.p_partkey
                 Sort Method: top-N heapsort  Memory: 25kB
                 ->  Seq Scan on part  (cost=0.00..68.00 rows=2000 width=8) (actual time=0.013..0.428 rows=2000 loops=1)
   ->  Nested Loop Left Join  (cost=0.00..45266972.75 rows=1 width=27) (actual time=299695.096..299695.096 rows=0 loops=1)
         Join Filter: ($0 IS NOT NULL)
         Filter: ((sample_0.l_orderkey IS NULL) AND (sample_0.l_shipmode IS NULL))
         Rows Removed by Filter: 3621030625
         ->  Seq Scan on lineitem ref_0  (cost=0.00..1969.75 rows=60175 width=11) (actual time=0.026..6.225 rows=60175 loops=1)
         ->  Materialize  (cost=0.00..2270.62 rows=60175 width=27) (actual time=0.000..2.554 rows=60175 loops=60175)
               ->  Seq Scan on lineitem sample_0  (cost=0.00..1969.75 rows=60175 width=27) (actual time=0.004..8.169 rows=60175 loops=1)
 Planning Time: 0.172 ms
 Execution Time: 299695.501 ms
(16 rows)

After I set enable_material to off, the same query run faster, as below:
set enable_material = off;
explain analyze  select
  subq_0.c0 as c0,
  subq_0.c1 as c1,
  subq_0.c2 as c2
from
  (select
        ref_0.l_shipmode as c0,
        sample_0.l_orderkey as c1,
        sample_0.l_quantity as c2,
        ref_0.l_orderkey as c3,
        sample_0.l_shipmode as c5,
        ref_0.l_shipinstruct as c6
      from
        public.lineitem as ref_0
          left join public.lineitem as sample_0
          on ((select p_partkey from public.part order by p_partkey limit 1)
                 is not NULL)
      where sample_0.l_orderkey is NULL) as subq_0
where subq_0.c5 is NULL
limit 1;
                                                                  QUERY PLAN                                                                  
-----------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=1078.00..91026185.57 rows=1 width=27) (actual time=192669.605..192670.425 rows=0 loops=1)
   InitPlan 1 (returns $0)
     ->  Limit  (cost=78.00..78.00 rows=1 width=8) (actual time=0.662..0.663 rows=1 loops=1)
           ->  Sort  (cost=78.00..83.00 rows=2000 width=8) (actual time=0.661..0.662 rows=1 loops=1)
                 Sort Key: part.p_partkey
                 Sort Method: top-N heapsort  Memory: 25kB
                 ->  Seq Scan on part  (cost=0.00..68.00 rows=2000 width=8) (actual time=0.017..0.430 rows=2000 loops=1)
   ->  Gather  (cost=1000.00..91026107.57 rows=1 width=27) (actual time=192669.604..192670.422 rows=0 loops=1)
         Workers Planned: 1
         Params Evaluated: $0
         Workers Launched: 1
         ->  Nested Loop Left Join  (cost=0.00..91025107.47 rows=1 width=27) (actual time=192588.143..192588.144 rows=0 loops=2)
               Join Filter: ($0 IS NOT NULL)
               Filter: ((sample_0.l_orderkey IS NULL) AND (sample_0.l_shipmode IS NULL))
               Rows Removed by Filter: 1810515312
               ->  Parallel Seq Scan on lineitem ref_0  (cost=0.00..1721.97 rows=35397 width=11) (actual time=0.007..3.797 rows=30088 loops=2)
               ->  Seq Scan on lineitem sample_0  (cost=0.00..1969.75 rows=60175 width=27) (actual time=0.000..2.637 rows=60175 loops=60175)
 Planning Time: 0.174 ms
 Execution Time: 192670.458 ms
(19 rows)

I debug the code and find consider_parallel_nestloop() doesn't consider materialized form of the cheapest inner path.
When enable_material = true,  we can see Material path won in first plan, but Parallel Seq Scan node doesn't add as outer path, which because
in try_partial_nestloop_path() , the cost of nestloop wat computed using seq scan path not material path. 

[1] include test table schema and data, you can repeat above problem.

I try fix this problem in attached patch, and I found pg12.12 also had this issue. Please review my patch, thanks! 

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
Richard Guo
Дата:

On Tue, Sep 5, 2023 at 4:52 PM tender wang <tndrwang@gmail.com> wrote:
   I recently run benchmark[1] on master, but I found performance problem as below:
...

I debug the code and find consider_parallel_nestloop() doesn't consider materialized form of the cheapest inner path.

Yeah, this seems an omission in commit 45be99f8.  I reviewed the patch
and here are some comments.

* I think we should not consider materializing the cheapest inner path
  if we're doing JOIN_UNIQUE_INNER, because in this case we have to
  unique-ify the inner path.

* I think we can check if it'd be parallel safe before creating the
  material path, thus avoid the creation in unsafe cases.

* I don't think the test case you added works for the code changes.
  Maybe a plan likes below is better:

explain (costs off)
select * from tenk1, tenk2 where tenk1.two = tenk2.two;
                  QUERY PLAN
----------------------------------------------
 Gather
   Workers Planned: 4
   ->  Nested Loop
         Join Filter: (tenk1.two = tenk2.two)
         ->  Parallel Seq Scan on tenk1
         ->  Materialize
               ->  Seq Scan on tenk2
(7 rows)

Thanks
Richard

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
tender wang
Дата:


Richard Guo <guofenglinux@gmail.com> 于2023年9月5日周二 18:51写道：

On Tue, Sep 5, 2023 at 4:52 PM tender wang <tndrwang@gmail.com> wrote:
   I recently run benchmark[1] on master, but I found performance problem as below:
...

I debug the code and find consider_parallel_nestloop() doesn't consider materialized form of the cheapest inner path.

Yeah, this seems an omission in commit 45be99f8.  I reviewed the patch
and here are some comments.

* I think we should not consider materializing the cheapest inner path
  if we're doing JOIN_UNIQUE_INNER, because in this case we have to
  unique-ify the inner path.
 
     That's right. The V2 patch has been fixed. 


* I think we can check if it'd be parallel safe before creating the
  material path, thus avoid the creation in unsafe cases.
       
    Agreed.
     
     
* I don't think the test case you added works for the code changes.
  Maybe a plan likes below is better:
 
      Agreed.

explain (costs off)
select * from tenk1, tenk2 where tenk1.two = tenk2.two;
                  QUERY PLAN
----------------------------------------------
 Gather
   Workers Planned: 4
   ->  Nested Loop
         Join Filter: (tenk1.two = tenk2.two)
         ->  Parallel Seq Scan on tenk1
         ->  Materialize
               ->  Seq Scan on tenk2
(7 rows)

Thanks
Richard
Вложения

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
Robert Haas
Дата:
On Tue, Sep 5, 2023 at 8:07 AM Richard Guo <guofenglinux@gmail.com> wrote:
> Yeah, this seems an omission in commit 45be99f8.

It's been a while, but I think I omitted this deliberately because I
didn't really understand the value of it and wanted to keep the
planning cost down.

The example query provided here seems rather artificial. Surely few
people write a join clause that references neither of the tables being
joined. Is there a more realistic case where this makes a big
difference?

--
Robert Haas
EDB: http://www.enterprisedb.com

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
Richard Guo
Дата:

On Fri, Sep 8, 2023 at 3:15 AM Robert Haas <robertmhaas@gmail.com> wrote:
The example query provided here seems rather artificial. Surely few
people write a join clause that references neither of the tables being
joined. Is there a more realistic case where this makes a big
difference?

Yes the given example query is not that convincing.  I tried a query
with plans as below (after some GUC setting) which might be more
realistic in real world.

unpatched:

explain select * from partsupp join lineitem on l_partkey > ps_partkey;
                                      QUERY PLAN
--------------------------------------------------------------------------------------
 Gather  (cost=0.00..5522666.44 rows=160466667 width=301)
   Workers Planned: 4
   ->  Nested Loop  (cost=0.00..5522666.44 rows=40116667 width=301)
         Join Filter: (lineitem.l_partkey > partsupp.ps_partkey)
         ->  Parallel Seq Scan on lineitem  (cost=0.00..1518.44 rows=15044 width=144)
         ->  Seq Scan on partsupp  (cost=0.00..267.00 rows=8000 width=157)
(6 rows)

patched:

explain select * from partsupp join lineitem on l_partkey > ps_partkey;
                                      QUERY PLAN
--------------------------------------------------------------------------------------
 Gather  (cost=0.00..1807085.44 rows=160466667 width=301)
   Workers Planned: 4
   ->  Nested Loop  (cost=0.00..1807085.44 rows=40116667 width=301)
         Join Filter: (lineitem.l_partkey > partsupp.ps_partkey)
         ->  Parallel Seq Scan on lineitem  (cost=0.00..1518.44 rows=15044 width=144)
         ->  Materialize  (cost=0.00..307.00 rows=8000 width=157)
               ->  Seq Scan on partsupp  (cost=0.00..267.00 rows=8000 width=157)
(7 rows)

The execution time (ms) are (avg of 3 runs):

unpatched:  71769.21
patched:    65510.04

So we can see some (~9%) performance gains in this case.

Thanks
Richard

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
tender wang
Дата:
Hi tom,
   Do you have any comments or suggestions on this issue? Thanks.

Richard Guo <guofenglinux@gmail.com> 于2023年9月8日周五 14:06写道：

On Fri, Sep 8, 2023 at 3:15 AM Robert Haas <robertmhaas@gmail.com> wrote:
The example query provided here seems rather artificial. Surely few
people write a join clause that references neither of the tables being
joined. Is there a more realistic case where this makes a big
difference?

Yes the given example query is not that convincing.  I tried a query
with plans as below (after some GUC setting) which might be more
realistic in real world.

unpatched:

explain select * from partsupp join lineitem on l_partkey > ps_partkey;
                                      QUERY PLAN
--------------------------------------------------------------------------------------
 Gather  (cost=0.00..5522666.44 rows=160466667 width=301)
   Workers Planned: 4
   ->  Nested Loop  (cost=0.00..5522666.44 rows=40116667 width=301)
         Join Filter: (lineitem.l_partkey > partsupp.ps_partkey)
         ->  Parallel Seq Scan on lineitem  (cost=0.00..1518.44 rows=15044 width=144)
         ->  Seq Scan on partsupp  (cost=0.00..267.00 rows=8000 width=157)
(6 rows)

patched:

explain select * from partsupp join lineitem on l_partkey > ps_partkey;
                                      QUERY PLAN
--------------------------------------------------------------------------------------
 Gather  (cost=0.00..1807085.44 rows=160466667 width=301)
   Workers Planned: 4
   ->  Nested Loop  (cost=0.00..1807085.44 rows=40116667 width=301)
         Join Filter: (lineitem.l_partkey > partsupp.ps_partkey)
         ->  Parallel Seq Scan on lineitem  (cost=0.00..1518.44 rows=15044 width=144)
         ->  Materialize  (cost=0.00..307.00 rows=8000 width=157)
               ->  Seq Scan on partsupp  (cost=0.00..267.00 rows=8000 width=157)
(7 rows)

The execution time (ms) are (avg of 3 runs):

unpatched:  71769.21
patched:    65510.04

So we can see some (~9%) performance gains in this case.

Thanks
Richard

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
David Rowley
Дата:
On Fri, 8 Sept 2023 at 09:41, Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Tue, Sep 5, 2023 at 8:07 AM Richard Guo <guofenglinux@gmail.com> wrote:
> > Yeah, this seems an omission in commit 45be99f8.
>
> It's been a while, but I think I omitted this deliberately because I
> didn't really understand the value of it and wanted to keep the
> planning cost down.

I think the value is potentially not having to repeatedly execute some
expensive rescan to the nested loop join once for each outer-side
tuple.

The planning cost is something to consider for sure, but it seems
strange that we deemed it worthy to consider material paths for the
non-parallel input paths but draw the line for the parallel/partial
ones. It seems to me that the additional costs and the possible
benefits are the same for both.

David

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
David Rowley
Дата:
On Fri, 8 Sept 2023 at 19:14, Richard Guo <guofenglinux@gmail.com> wrote:
> explain select * from partsupp join lineitem on l_partkey > ps_partkey;
>                                       QUERY PLAN
> --------------------------------------------------------------------------------------
>  Gather  (cost=0.00..1807085.44 rows=160466667 width=301)
>    Workers Planned: 4
>    ->  Nested Loop  (cost=0.00..1807085.44 rows=40116667 width=301)
>          Join Filter: (lineitem.l_partkey > partsupp.ps_partkey)
>          ->  Parallel Seq Scan on lineitem  (cost=0.00..1518.44 rows=15044 width=144)
>          ->  Materialize  (cost=0.00..307.00 rows=8000 width=157)
>                ->  Seq Scan on partsupp  (cost=0.00..267.00 rows=8000 width=157)
> (7 rows)
>
> The execution time (ms) are (avg of 3 runs):
>
> unpatched:  71769.21
> patched:    65510.04

This gap would be wider if the partsupp Seq Scan were filtering off
some rows and wider still if you added more rows to lineitem.
However, a clauseless seqscan is not the most compelling use case
below a material node. The inner side of the nested loop could be some
subquery that takes 6 days to complete. Running the 6 day query ~15044
times seems like something that would be good to avoid.

It seems worth considering Material paths to me.  I think that the
above example could be tuned any way you like to make it look better
or worse.

David

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
Alena Rybakina
Дата:

Hi!

Thank you for your work on the subject.


I reviewed your patch and found that your commit message does not fully explain your code, in addition, I found several spelling mistakes.

I think it's better to change to:With parallel seqscan, we should consider materializing the cheapest inner path in
case of nested loop if it doesn't contain a unique node or it is unsafe to use it in a subquery.


Besides, I couldn't understand why we again check that material path is safe?

if (matpath != NULL && matpath->parallel_safe)
            try_partial_nestloop_path(root, joinrel, outerpath, matpath,
                                      pathkeys, jointype, extra);

-- 
Regards,
Alena Rybakina

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
"Andrey M. Borodin"
Дата:

> On 27 Sep 2023, at 16:06, tender wang <tndrwang@gmail.com> wrote:
>
>    Do you have any comments or suggestions on this issue? Thanks.
Hi Tender,

there are some review comments in the thread, that you might be interested in.
I'll mark this [0] entry "Waiting on Author" and move to next CF.

Thanks!


Best regards, Andrey Borodin.

[0]https://commitfest.postgresql.org/47/4549/

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
Tender Wang
Дата:


Andrey M. Borodin <x4mmm@yandex-team.ru> 于2024年4月8日周一 17:40写道：


> On 27 Sep 2023, at 16:06, tender wang <tndrwang@gmail.com> wrote:
>
>    Do you have any comments or suggestions on this issue? Thanks.
Hi Tender,

there are some review comments in the thread, that you might be interested in.
I'll mark this [0] entry "Waiting on Author" and move to next CF.

 Thank you for the reminder.  I will update the patch later.
I also deeply hope to get more advice about this patch.
(even the advice that not worth  continuint to work on this patch).

Thanks.

Thanks!


Best regards, Andrey Borodin.

[0]https://commitfest.postgresql.org/47/4549/


--
Tender Wang
OpenPie:  https://en.openpie.com/

Re: Should consider materializing the cheapest inner path in consider_parallel_nestloop()

От
Tender Wang
Дата:


Andrey M. Borodin <x4mmm@yandex-team.ru> 于2024年4月8日周一 17:40写道：


> On 27 Sep 2023, at 16:06, tender wang <tndrwang@gmail.com> wrote:
>
>    Do you have any comments or suggestions on this issue? Thanks.
Hi Tender,

there are some review comments in the thread, that you might be interested in.
I'll mark this [0] entry "Waiting on Author" and move to next CF.

Thanks!


Best regards, Andrey Borodin.

[0]https://commitfest.postgresql.org/47/4549/

I have rebased master and fixed a plan diff case.
--
Tender Wang
OpenPie:  https://en.openpie.com/
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