Details
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Bug
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Status: Closed (View Workflow)
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Minor
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Resolution: Fixed
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10.0.3
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None
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Linux/Ubuntu/Precise/LXContainer
Description
Creating a pivot table (Connect SE) and selecting from the table works.
Doing a second select the connection dies.
MariaDB [test]> select * from pivottet; |
ERROR 2013 (HY000): Lost connection to MySQL server during query |
MariaDB [test]> create table pivottet engine=connect table_type=pivot tabname=salary; |
Query OK, 0 rows affected (0.02 sec) |
MariaDB [test]> select * from pivottet; |
+--------+------+-----+------+-----+ |
| sellet | 1 | 2 | 3 | 4 |
|
+--------+------+-----+------+-----+ |
| 1 | 100 | 300 | 1000 | 0 |
|
| 2 | 1000 | 100 | 0 | 0 |
|
| 3 | 0 | 0 | 0 | 500 |
|
+--------+------+-----+------+-----+ |
3 rows in set (0.00 sec) |
MariaDB [test]> select * from pivottet; |
ERROR 2013 (HY000): Lost connection to MySQL server during query |
That is written into the error log:
Jul 9 10:17:56 localhost mysqld: 130709 10:17:56 [Warning] Aborted connection 264 to db: 'test' user: 'root' host: 'localhost' (Unknown error)
|
Regards
Erkan
Attachments
Activity
Further investigation shows that this bug is related to the use of the query cache. Before this is fixed (by preventing queries on PIVOT tables to be cached, as for queries on partitioned tables) a bypass is to specify the query_cache_size variable to 0. This makes the query cache not used.
Because CONNECT works on external data that can be modified any time out of MariaDB, it must not use the query cache. Therefore, query cache has been permanently disabled for CONNECT tables.
Sorry erkan, I wrongly thought it was working on ubuntu but it turned
out that it did not and disconnected on the second,
and further, tries to select the table. So this is not closed but not
going to be solved soon because I get no information
on the possible error. For instance, under GDB nothing is told, and
looking at the traces I have done, mysqld disconnects
even before creating the CONNECT thread supposed to handle the query!
Because of this, and also on some valgring warnings, the next version of
CONNECT will not support the PIVOT type, hoping
that will be temporarily...
Regards,
Olivier