Re: Gather Merge

På torsdag 09. mars 2017 kl. 18:09:45, skrev Robert Haas <robertmhaas(at)gmail(dot)com
<mailto: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_id FROM origo_email_delivery del JOIN
origo_email_message emON (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_idIN ( SELECT ea_owner.message_id FROM origo_email_address_owner
ea_ownerWHERE 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?
 
If I select del.entity_id, it works:
 
EXPLAIN ANALYSE SELECT del.entity_id FROM origo_email_delivery del JOIN
origo_email_message emON (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_idIN ( SELECT ea_owner.message_id FROM origo_email_address_owner
ea_ownerWHERE 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