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for ALTER TABLE + MERGE tables The patch for Bug#56292 changed how metadata locks are taken for MERGE tables. After the patch, locking the MERGE table will also lock the children tables with the same metadata lock type. This means that LOCK TABLES on a MERGE table also will implicitly do LOCK TABLES on the children tables. A consequence of this change, is that it is possible to do LOCK TABLES on a child table both explicitly and implicitly with the same statement and that these two locks can be of different strength. For example, LOCK TABLES child READ, merge WRITE. In LOCK TABLES mode, we are not allowed to take new locks and each statement must therefore try to find an existing TABLE instance with a suitable lock. The code that searched for a suitable TABLE instance, only considered table level locks. If a child table was locked twice, it was therefore possible for this code to find a TABLE instance with suitable table level locks but without suitable metadata lock. This problem caused the assert in upgrade_shared_lock_to_exclusive() to be triggered as it tried to upgrade a MDL_SHARED lock to EXCLUSIVE. The problem was a regression caused by the patch for Bug#56292. This patch fixes the problem by partially reverting the changes done by Bug#56292. Now, the children tables will only use the same metadata lock as the MERGE table for MDL_SHARED_NO_WRITE when not in locked tables mode. This means that LOCK TABLE on a MERGE table will not implicitly lock the children tables. This still fixes the original problem in Bug#56292 without causing a regression. Test case added to merge.test.
This directory contains a test suite for the MySQL daemon. To run the currently existing test cases, simply execute ./mysql-test-run in this directory. It will fire up the newly built mysqld and test it. Note that you do not have to have to do "make install", and you could actually have a co-existing MySQL installation. The tests will not conflict with it. All tests must pass. If one or more of them fail on your system, please read the following manual section for instructions on how to report the problem: http://dev.mysql.com/doc/mysql/en/mysql-test-suite.html If you want to use an already running MySQL server for specific tests, use the --extern option to mysql-test-run. Please note that in this mode, the test suite expects you to provide the names of the tests to run. For example, here is the command to run the "alias" and "analyze" tests with an external server: mysql-test-run --extern alias analyze To match your setup, you might also need to provide --socket, --user, and other relevant options. With no test cases named on the command line, mysql-test-run falls back to the normal "non-extern" behavior. The reason for this is that some tests cannot run with an external server. You can create your own test cases. To create a test case, create a new file in the t subdirectory using a text editor. The file should have a .test extension. For example: xemacs t/test_case_name.test In the file, put a set of SQL statements that create some tables, load test data, and run some queries to manipulate it. We would appreciate it if you name your test tables t1, t2, t3 ... (to not conflict too much with existing tables). Your test should begin by dropping the tables you are going to create and end by dropping them again. This ensures that you can run the test over and over again. If you are using mysqltest commands (like result file names) in your test case, you should create the result file as follows: mysql-test-run --record test_case_name or mysqltest --record < t/test_case_name.test If you only have a simple test cases consisting of SQL statements and comments, you can create the test case in one of the following ways: mysql-test-run --record test_case_name mysql test < t/test_case_name.test > r/test_case_name.result mysqltest --record --record-file=r/test_case_name.result < t/test_case_name.test When this is done, take a look at r/test_case_name.result - If the result is incorrect, you have found a bug. In this case, you should edit the test result to the correct results so that we can verify that the bug is corrected in future releases. To submit your test case, put your .test file and .result file(s) into a tar.gz archive, add a README that explains the problem, ftp the archive to ftp://support.mysql.com/pub/mysql/secret/ and send a mail to bugs@lists.mysql.com