Re: [HACKERS] Partition-wise aggregation/grouping

Hi Jeevan,

while testing latest v3 patches, I am  getting a server crash if I reset partition_wise_agg_cost_factor, please take a look.

CREATE TABLE lp (a TEXT, b FLOAT, c INT) PARTITION BY LIST(c);
CREATE TABLE lp1 PARTITION OF lp FOR VALUES IN (10,20);
CREATE TABLE lp2 PARTITION OF lp FOR VALUES IN (30,40);

INSERT INTO lp VALUES ('a1',800, 20);
INSERT INTO lp VALUES ('a2',1250,30);
INSERT INTO lp VALUES ('a3',2975,20);
INSERT INTO lp VALUES ('a3',2850,30);

postgres=# SET enable_partition_wise_agg TO true;
SET
postgres=# SET partition_wise_agg_cost_factor TO 0.5;
SET
postgres=#
postgres=# SELECT MAX(b), AVG(b) FROM lp GROUP BY a HAVING a = 'a3' ORDER BY 1,2;
 max  |  avg  
------+--------
 2975 | 2912.5
(1 row)

postgres=# RESET partition_wise_agg_cost_factor;
RESET
postgres=#
postgres=# SELECT MAX(b), AVG(b) FROM lp GROUP BY a HAVING a = 'a3' ORDER BY 1,2;
server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

Thanks & Regards,
Rajkumar Raghuwanshi
QMG, EnterpriseDB Corporation