Tom Lane wrote:
Rajesh Kumar Mallah <mallah@trade-india.com> writes:
It does.
And?
Yep the problem of original posting could be replicated on
disabling hash aggregates. On disabling i could get the repeated rows.
Regds
Mallah.
rt2=# SET enable_hashagg TO off;
SET
Time: 329.533 ms
rt2=# explain analyze SELECT name from users_sample group by name having count(*) > 1 ;
+------------------------------------------------------------------------------------------------------------------------------+
| QUERY PLAN |
+------------------------------------------------------------------------------------------------------------------------------+
| GroupAggregate (cost=69.83..78.33 rows=200 width=78) (actual time=2411.411..2749.733 rows=4 loops=1) |
| Filter: (count(*) > 1) |
| -> Sort (cost=69.83..72.33 rows=1000 width=78) (actual time=2411.300..2532.821 rows=100489 loops=1) |
| Sort Key: name |
| -> Seq Scan on users_sample (cost=0.00..20.00 rows=1000 width=78) (actual time=0.024..170.258 rows=100489 loops=1) |
| Total runtime: 2915.439 ms |
+------------------------------------------------------------------------------------------------------------------------------+
(6 rows)
Time: 3265.102 ms
rt2=# SELECT name from users_sample group by name having count(*) > 1 ;
+----------------------+
| name |
+----------------------+
| ��� |
| ����163.com |
| �@hotmail.com |
| p� |
+----------------------+
(4 rows)
Time: 3358.030 ms
rt2=# SET enable_hashagg TO on;
SET
Time: 330.148 ms
rt2=# SELECT name from users_sample group by name having count(*) > 1 ;
+------+
| name |
+------+
+------+
(0 rows)
Time: 752.395 ms
rt2=#Tom Lane wrote:
Hm. Does EXPLAIN show that the GROUP BY query is using hash
aggregation? Does its behavior change if you turn off enable_hashagg?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
regards, tom lane
