Details
-
Bug
-
Status: Closed (View Workflow)
-
Major
-
Resolution: Fixed
-
10.2(EOL)
Description
Note: results below are from 10.2 348ccb6f038a6c1.
create table t1 (i int); |
insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); |
select i, Min(i) OVER (PARTITION BY i) as f from (select * from t1) as tt order by i; |
|
Actual result |
+------+------+ |
| i | f |
|
+------+------+ |
| 1 | 10 |
|
| 2 | 10 |
|
| 3 | 10 |
|
| 4 | 10 |
|
| 5 | 10 |
|
| 6 | 10 |
|
| 7 | 10 |
|
| 8 | 10 |
|
| 9 | 10 |
|
| 10 | 10 |
|
+------+------+ |
10 rows in set (0.00 sec) |
Without the subquery, the result is different:
MariaDB [test]> select i, Min(i) OVER (PARTITION BY i) as f from t1 as tt order by i; |
+------+------+ |
| i | f |
|
+------+------+ |
| 1 | 1 |
|
| 2 | 2 |
|
| 3 | 3 |
|
| 4 | 4 |
|
| 5 | 5 |
|
| 6 | 6 |
|
| 7 | 7 |
|
| 8 | 8 |
|
| 9 | 9 |
|
| 10 | 10 |
|
+------+------+ |
10 rows in set (0.01 sec) |
PostgreSQL 9.4 returns the same for both queries:
postgres=# select i, Min(i) OVER (PARTITION BY i) as f from t1 as tt order by i; |
i | f
|
----+----
|
1 | 1
|
2 | 2
|
3 | 3
|
4 | 4
|
5 | 5
|
6 | 6
|
7 | 7
|
8 | 8
|
9 | 9
|
10 | 10
|
(10 rows) |
postgres=# select i, Min(i) OVER (PARTITION BY i) as f from (select * from t1) as tt order by i; |
i | f
|
----+----
|
1 | 1
|
2 | 2
|
3 | 3
|
4 | 4
|
5 | 5
|
6 | 6
|
7 | 7
|
8 | 8
|
9 | 9
|
10 | 10
|
(10 rows) |
Attachments
Issue Links
- relates to
-
MDEV-9896 Testing for window functions
-
- Open
-
Activity
| Summary | Wrong result while using aggregate window function on subquery | Wrong result upon using aggregate window function selecting from subquery |
| Labels | 10.2-rc |
| Assignee | Vicentiu Ciorbaru [ cvicentiu ] | Igor Babaev [ igor ] |
| Status | Open [ 1 ] | In Progress [ 3 ] |
| Summary | Wrong result upon using aggregate window function selecting from subquery | Wrong results upon using window function withmin/max aggregation |
| Summary | Wrong results upon using window function withmin/max aggregation | Wrong results upon using window function with min/max aggregation |
| Status | In Progress [ 3 ] | Stalled [ 10000 ] |
| Fix Version/s | 10.2.4 [ 22116 ] | |
| Fix Version/s | 10.2 [ 14601 ] | |
| Resolution | Fixed [ 1 ] | |
| Status | Stalled [ 10000 ] | Closed [ 6 ] |
| Workflow | MariaDB v3 [ 79127 ] | MariaDB v4 [ 151502 ] |
We also have the following problem with window functions using min/max aggregations:
create table t1 (i int, b int);insert into t1 values(1,1),(2,1),(3,1),(4,4),(5,4),(6,4),(7,8),(8,8),(9,8),(10,8);MariaDB [test]> select b, min(i+10) over (partition by b) as f-> from t1 as tt-> order by i;+------+------+| b | f |+------+------+| 1 | 20 || 1 | 20 || 1 | 20 || 4 | 20 || 4 | 20 || 4 | 20 || 8 | 20 || 8 | 20 || 8 | 20 || 8 | 20 |+------+------+The cause of both problems is the same: splitting arguments of aggregate functions used in window functions has not been done
correctly unless the argument is just a field. In our cases the argument either an Item_direct_ref or Item_func_plus.