Re: Gather Merge

On Fri, Mar 10, 2017 at 1:44 PM, Andreas Joseph Krogh <andreas(at)visena(dot)com>
wrote:

> På torsdag 09. mars 2017 kl. 18:09:45, skrev Robert Haas <
> robertmhaas(at)gmail(dot)com>:
>
> On Thu, Mar 9, 2017 at 11:25 AM, Rushabh Lathia
> <rushabh(dot)lathia(at)gmail(dot)com> wrote:
> > I don't see this failure with the patch. Even I forced the gather merge
> > in the above query and that just working fine.
> >
> > Attaching patch, with the discussed changes.
>
> Committed.
>
>
>
> I'm still getting (as of 9c2635e26f6f4e34b3b606c0fc79d0e111953a74):
> ERROR: GatherMerge child's targetlist doesn't match GatherMerge
>
>
> from this query:
>
>
> EXPLAIN ANALYSE SELECT em.entity_idFROM origo_email_delivery del
> JOIN origo_email_message em ON (del.message_id = em.entity_id)WHERE 1 = 1 AND del.owner_id = 3 AND (
> del.from_entity_id = 279519 OR del.from_entity_id = 3 AND em.entity_id IN (
> SELECT ea_owner.message_id
> FROM origo_email_address_owner ea_owner
> WHERE ea_owner.recipient_id = 279519 )
> )
> ORDER BY del.received_timestamp DESCLIMIT 101 OFFSET 0;
>
>
> Is this known or shall I provide more info/schema etc?
>

Please provide the reproducible test if possible.

>
> If I select del.entity_id, it works:
>
>
> EXPLAIN ANALYSE SELECT del.entity_id
> FROM origo_email_delivery del
> JOIN origo_email_message em ON (del.message_id = em.entity_id)
> WHERE 1 = 1 AND del.owner_id = 3 AND (
> del.from_entity_id = 279519 OR del.from_entity_id = 3 AND em.entity_id IN (
> SELECT ea_owner.message_id
> FROM origo_email_address_owner ea_owner
> WHERE ea_owner.recipient_id = 279519 )
> )
>
> ORDER BY del.received_timestamp DESC LIMIT 101 OFFSET 0;
>
>
> Plan is:
> │ Limit (cost=1259.72..15798.21 rows=101 width=16) (actual
> time=152.946..153.269 rows=34 loops=1)
> │
>
> │ -> Gather Merge (cost=1259.72..3139414.43 rows=21801 width=16)
> (actual time=152.945..153.264 rows=34 loops=1)
>
> │
> │ Workers Planned: 4
>
>
> │
> │ Workers Launched: 4
>
>
> │
> │ -> Nested Loop (cost=259.66..3135817.66 rows=5450 width=16)
> (actual time=95.295..137.549 rows=7 loops=5)
> │
> │ -> Parallel Index Scan Backward using
> origo_email_received_idx on origo_email_delivery del (cost=0.42..312163.56
> rows=10883 width=32) (actual time=0.175..121.434 rows=6540 loops=5)
> │
> │ Filter: ((owner_id = 3) AND ((from_entity_id =
> 279519) OR (from_entity_id = 3)))
>
> │
> │ Rows Removed by Filter: 170355
>
>
> │
> │ -> Index Only Scan using origo_email_message_pkey on
> origo_email_message em (cost=259.24..259.45 rows=1 width=8) (actual
> time=0.002..0.002 rows=0 loops=32699) │
> │ Index Cond: (entity_id = del.message_id)
>
>
> │
> │ Filter: ((del.from_entity_id = 279519) OR
> ((del.from_entity_id = 3) AND (hashed SubPlan 1)))
>
> │
> │ Rows Removed by Filter: 1
>
>
> │
> │ Heap Fetches: 0
>
>
> │
> │ SubPlan 1
>
>
> │
> │ -> Index Scan using origo_email_address_owner_recipient_id_idx
> on origo_email_address_owner ea_owner (cost=0.43..258.64 rows=69 width=8)
> (actual time=0.032..0.294 rows=175 loops=5) │
> │ Index Cond: (recipient_id = 279519)
>
>
> │
> │ Planning time: 1.372 ms
>
>
> │
> │ Execution time: 170.859 ms
>
>
> │
>
>
>
> --
> *Andreas Joseph Krogh*
>
>

--
Rushabh Lathia