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  1. MariaDB Server
  2. MDEV-774

LP:948583 - Stored procedure doesn't not take into account ALTER TABLE, causes wrong result or replication abort

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      The problem is reproducible on all of MariaDB 5.1, 5.2, 5.3, 5.5, MySQL 5.1, 5.5, 5.6, and has also been filed as http://bugs.mysql.com/bug.php?id=64574.

      A stored procedure or a trigger, having been executed once, on the second run might not take into account changes in a table structure, which causes a wrong result on the server where it is run, and also might cause SQL slave abort if the master wrongly returns OK after such a change, while the slave throws the expected error.

      Below are two test cases. The first one is for the basic scenario: the initial execution of the stored procedure ends with the expected error, then the table structure gets fixed, but the procedure fails anyway, with

      query 'CALL p()' failed: 1054: Unknown column 'test.t2.b' in 'field list'

      The second test case is a reversed scenario – first execution of the procedure runs fine (correctly), then the table structure is altered, and the second execution must fail, but it does not on master; instead, the statement is written in the binlog with error code 0 and later fails on slave, thus causing a replication failure:

      1136 Error 'Column count doesn't match value count at row 1' on query.

      I found the ancient bug http://bugs.mysql.com/bug.php?id=6120 which looks similar, only for views, but it was fixed ages ago.

      Test case 1 (wrong result - the last procedure call fails while it shouldn't)

      CREATE TABLE t1 (a INT);
      CREATE TABLE t2 (b INT, c INT);
       
      --delimiter |
      CREATE PROCEDURE p()
      BEGIN
        INSERT INTO t1 SELECT * FROM t2;
      END |
      --delimiter ;
       
      --error ER_WRONG_VALUE_COUNT_ON_ROW
      CALL p();
      ALTER TABLE t2 DROP COLUMN b;
      CALL p();
       

      Test case 2 (replication failure)

      --source include/master-slave.inc
      CREATE TABLE t1 (a INT);
      CREATE TABLE t2 (b INT);
       
      --delimiter |
      CREATE PROCEDURE p()
      BEGIN
        INSERT INTO t1 SELECT * FROM t2;
      END |
      --delimiter ;
       
      CALL p();
      ALTER TABLE t2 ADD COLUMN c INT;
      CALL p();
      --sync_slave_with_master
       

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              • Assignee:
                Unassigned
                Reporter:
                elenst Elena Stepanova
              • Votes:
                2 Vote for this issue
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                • Created:
                  Updated: