Re: Bugreport: incorrect result in 16.1 in query with string_agg(distinct+json_build_object - Mailing list pgsql-bugs
| From | Oscar van Baten |
|---|---|
| Subject | Re: Bugreport: incorrect result in 16.1 in query with string_agg(distinct+json_build_object |
| Date | |
| Msg-id | CAC+9yuOrYon-TSnK2F7xDDEWAemxapEErOE3KM0QBCJtQtaUYQ@mail.gmail.com Whole thread Raw |
| In response to | Re: Bugreport: incorrect result in 16.1 in query with string_agg(distinct+json_build_object (Tom Lane <tgl@sss.pgh.pa.us>) |
| Responses |
Re: Bugreport: incorrect result in 16.1 in query with string_agg(distinct+json_build_object
(Oscar van Baten <info@oxcro.com>)
Re: Bugreport: incorrect result in 16.1 in query with string_agg(distinct+json_build_object (Tom Lane <tgl@sss.pgh.pa.us>) |
| List | pgsql-bugs |
Hi Tom,
There you go:
v14.7
QUERY PLAN |
----------------------------------------------------------------------------------------------------------------------------------------+
GroupAggregate (cost=94.38..128.98 rows=200 width=96) |
Output: a.id, string_agg(DISTINCT 'val_B'::text, ', '::text), (json_agg(json_build_object('val_1', a.id, 'val_2', (SubPlan 1))))::text|
Group Key: a.id |
-> Sort (cost=94.38..97.78 rows=1360 width=32) |
Output: a.id |
Sort Key: a.id |
-> Seq Scan on pg_temp_684.alldata a (cost=0.00..23.60 rows=1360 width=32) |
Output: a.id |
SubPlan 1 |
-> Result (cost=0.00..0.01 rows=1 width=32) |
Output: a.id |
Settings: effective_cache_size = '8014960kB', jit = 'off', search_path = 'public, public, "$user"' |
Query Identifier: -1271634773772018342 |
v16.1
QUERY PLAN |
----------------------------------------------------------------------------------------------------------------------------------------+
GroupAggregate (cost=94.38..128.98 rows=200 width=96) |
Output: a.id, string_agg(DISTINCT 'val_B'::text, ', '::text), (json_agg(json_build_object('val_1', a.id, 'val_2', (SubPlan 1))))::text|
Group Key: a.id |
-> Sort (cost=94.38..97.78 rows=1360 width=32) |
Output: a.id |
Sort Key: a.id |
-> Seq Scan on pg_temp.alldata a (cost=0.00..23.60 rows=1360 width=32) |
Output: a.id |
SubPlan 1 |
-> Result (cost=0.00..0.01 rows=1 width=32) |
Output: a.id |
Settings: effective_cache_size = '16179496kB', jit = 'off', temp_buffers = '64MB', search_path = 'public, public, "$user"' |
Query Identifier: 1935934247983289476 |
Will try to compare the planner settings too.
Regards,
Oscar
There you go:
v14.7
QUERY PLAN |
----------------------------------------------------------------------------------------------------------------------------------------+
GroupAggregate (cost=94.38..128.98 rows=200 width=96) |
Output: a.id, string_agg(DISTINCT 'val_B'::text, ', '::text), (json_agg(json_build_object('val_1', a.id, 'val_2', (SubPlan 1))))::text|
Group Key: a.id |
-> Sort (cost=94.38..97.78 rows=1360 width=32) |
Output: a.id |
Sort Key: a.id |
-> Seq Scan on pg_temp_684.alldata a (cost=0.00..23.60 rows=1360 width=32) |
Output: a.id |
SubPlan 1 |
-> Result (cost=0.00..0.01 rows=1 width=32) |
Output: a.id |
Settings: effective_cache_size = '8014960kB', jit = 'off', search_path = 'public, public, "$user"' |
Query Identifier: -1271634773772018342 |
v16.1
QUERY PLAN |
----------------------------------------------------------------------------------------------------------------------------------------+
GroupAggregate (cost=94.38..128.98 rows=200 width=96) |
Output: a.id, string_agg(DISTINCT 'val_B'::text, ', '::text), (json_agg(json_build_object('val_1', a.id, 'val_2', (SubPlan 1))))::text|
Group Key: a.id |
-> Sort (cost=94.38..97.78 rows=1360 width=32) |
Output: a.id |
Sort Key: a.id |
-> Seq Scan on pg_temp.alldata a (cost=0.00..23.60 rows=1360 width=32) |
Output: a.id |
SubPlan 1 |
-> Result (cost=0.00..0.01 rows=1 width=32) |
Output: a.id |
Settings: effective_cache_size = '16179496kB', jit = 'off', temp_buffers = '64MB', search_path = 'public, public, "$user"' |
Query Identifier: 1935934247983289476 |
Will try to compare the planner settings too.
Regards,
Oscar
Op wo 3 jan 2024 om 17:56 schreef Tom Lane <tgl@sss.pgh.pa.us>:
Oscar van Baten <info@oxcro.com> writes:
> We've upgraded one of our instances from 14.10 to 16.1 at AWS
> All fine, except for a certain output which became different.
> At another instance running at 14.7 we are able to reproduce this correct
> answer.
> Removing the `DISTINCT` or replacing `(SELECT a.id)` with `a.id` does solve
> it.
> It looks like a reference issue.
> You can reproduce with the query below.
Hi, I failed to reproduce this. I get the expected output
table_value | string_agg_value | zzz_2
-------------+------------------+------------------------------------------
val_A | val_B | [{"val_1" : "val_A", "val_2" : "val_A"}]
(1 row)
both in HEAD and at 16.1 release (3edc6580c). It seems to me that
either you have some relevant non-default planner setting, or this
is an AWS-specific bug. Could we see the output of
EXPLAIN (VERBOSE, SETTINGS)
for this query on the troublesome system?
We do have an open report of a problem with DISTINCT aggregates,
https://www.postgresql.org/message-id/flat/18264-e363593d7e9feb7d%40postgresql.org
but it's unclear whether this is the same.
regards, tom lane
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