Re: [HACKERS] Partition-wise aggregation/grouping

> On Thu, Dec 14, 2017 at 4:01 PM, Ashutosh Bapat <
> ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
>
>>
>> +
>> +-- Partial aggregation as GROUP BY clause does not match with PARTITION
>> KEY
>> +EXPLAIN (COSTS OFF)
>> +SELECT b, sum(a), count(*) FROM pagg_tab GROUP BY b ORDER BY 1, 2, 3;
>> + QUERY PLAN
>> +----------------------------------------------------------------
>> + Sort
>> + Sort Key: pagg_tab_p1.b, (sum(pagg_tab_p1.a)), (count(*))
>> + -> Finalize GroupAggregate
>> + Group Key: pagg_tab_p1.b
>> + -> Sort
>> + Sort Key: pagg_tab_p1.b
>> + -> Append
>> + -> Partial HashAggregate
>> + Group Key: pagg_tab_p1.b
>> + -> Seq Scan on pagg_tab_p1
>> + -> Partial HashAggregate
>> + Group Key: pagg_tab_p2_s1.b
>> + -> Append
>> + -> Seq Scan on pagg_tab_p2_s1
>> + -> Seq Scan on pagg_tab_p2_s2
>> + -> Partial HashAggregate
>> + Group Key: pagg_tab_p3_s1.b
>> + -> Append
>> + -> Seq Scan on pagg_tab_p3_s1
>> + -> Seq Scan on pagg_tab_p3_s2
>> +(20 rows)
>>
>> Why aren't we seeing partial aggregation paths for level two and below
>> partitions?
>>
>
>>
> In this version of the patch I have not recursed into next level.
> Will work on it and submit changes in the next patch-set.
>

Attached new set of patches adding this. Only patch 0007 (main patch) and
0008 (testcase patch) has changed.

>
Please have a look and let me know if I missed any.

Thanks
--
Jeevan Chalke
Technical Architect, Product Development
EnterpriseDB Corporation
The Enterprise PostgreSQL Company