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  1. MariaDB Server
  2. MDEV-4771

Connect SE: Connection dies using table_type=pivor

Details

    • Bug
    • Status: Closed (View Workflow)
    • Minor
    • Resolution: Fixed
    • 10.0.3
    • 10.0.4
    • None
    • 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

          erkules erkan yanar created issue -
          elenst Elena Stepanova made changes -
          Field Original Value New Value
          Fix Version/s 10.0.4 [ 13101 ]
          Assignee Alexander Barkov [ bar ]
          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

          #v+
          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

          #v-

          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


          Creating a pivot table (Connect SE) and selecting from the table works.
          Doing a second select the connection dies.

          {code:sql}
           MariaDB [test]> select * from pivottet;
          ERROR 2013 (HY000): Lost connection to MySQL server during query
          {code}

          {code:sql}
          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
          {code}

          That is written into the error log:
          {noformat}
          Jul 9 10:17:56 localhost mysqld: 130709 10:17:56 [Warning] Aborted connection 264 to db: 'test' user: 'root' host: 'localhost' (Unknown error)
          {noformat}

          Regards
          Erkan
          Labels connect-engine
          bar Alexander Barkov made changes -
          Assignee Alexander Barkov [ bar ] Olivier Bertrand [ bertrandop ]

          I could not reproduce such error with the current version of CONNECT.

          Do debug I need to know exactly what was executed and, in particular, to
          have the salary table.
          How can I get that from Erkan?

          Regards, Olivier

          bertrandop Olivier Bertrand added a comment - I could not reproduce such error with the current version of CONNECT. Do debug I need to know exactly what was executed and, in particular, to have the salary table. How can I get that from Erkan? Regards, Olivier
          erkules erkan yanar added a comment -

          like that:

          #v
          CREATE TABLE `salary` (
          `sellet` int(11) DEFAULT NULL,
          `company` int(11) DEFAULT NULL,
          `volume` int(11) DEFAULT NULL
          ) ENGINE=InnoDB DEFAULT CHARSET=latin1
          #v-

          erkules erkan yanar added a comment - like that: #v CREATE TABLE `salary` ( `sellet` int(11) DEFAULT NULL, `company` int(11) DEFAULT NULL, `volume` int(11) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 #v-

          Thanks, I shall work on it.
          Regards,
          Olivier

          bertrandop Olivier Bertrand added a comment - Thanks, I shall work on it. Regards, Olivier

          Cannot reproduce on Windows and ubuntu

          bertrandop Olivier Bertrand added a comment - Cannot reproduce on Windows and ubuntu
          bertrandop Olivier Bertrand made changes -
          Resolution Cannot Reproduce [ 5 ]
          Status Open [ 1 ] Closed [ 6 ]
          erkules erkan yanar added a comment -

          So it's 'gone' with the current version or some settings on my side.
          Nevertheless Im gonna check the next mariadb release.

          erkules erkan yanar added a comment - So it's 'gone' with the current version or some settings on my side. Nevertheless Im gonna check the next mariadb release.

          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

          bertrandop Olivier Bertrand added a comment - 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

          Is indeed failing on Linux

          bertrandop Olivier Bertrand added a comment - Is indeed failing on Linux
          bertrandop Olivier Bertrand made changes -
          Resolution Cannot Reproduce [ 5 ]
          Status Closed [ 6 ] Reopened [ 4 ]

          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.

          bertrandop Olivier Bertrand added a comment - 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.
          erkules erkan yanar added a comment -

          Ahoi Olivier,
          yes setting query_cache_size=0 worked.

          Thx!

          erkules erkan yanar added a comment - Ahoi Olivier, yes setting query_cache_size=0 worked. Thx!

          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.

          bertrandop Olivier Bertrand added a comment - 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.
          bertrandop Olivier Bertrand made changes -
          Resolution Fixed [ 1 ]
          Status Reopened [ 4 ] Closed [ 6 ]
          serg Sergei Golubchik made changes -
          Workflow defaullt [ 27906 ] MariaDB v2 [ 46111 ]
          ratzpo Rasmus Johansson (Inactive) made changes -
          Workflow MariaDB v2 [ 46111 ] MariaDB v3 [ 64201 ]
          serg Sergei Golubchik made changes -
          Workflow MariaDB v3 [ 64201 ] MariaDB v4 [ 146854 ]

          People

            bertrandop Olivier Bertrand
            erkules erkan yanar
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            Dates

              Created:
              Updated:
              Resolved:

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