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The result of materialization of the right part of an IN subquery predicate is placed into a temporary table. Each row of the materialized table is distinct. A unique key over all fields of the temporary table is defined and created. It allows to perform key look-ups into the table. The table created for a materialized subquery can be accessed by key as any other table. The function best_access-path search for the best access to join a table to a given partial join. With some where conditions this function considers a possibility of a ref_or_null access. If such access employs the unique key on the temporary table then when estimating the cost this access the function tries to use the array rec_per_key. Yet, such array is not built for this unique key. This causes a crash of the server. Rows returned by the subquery that contain nulls don't have to be placed into temporary table, as they cannot be match any row produced by the left part of the subquery predicate. So all fields of the temporary table can be defined as non-nullable. In this case any ref_or_null access to the temporary table does not make any sense and it does not make sense to estimate such an access. The fix makes sure that the temporary table for a materialized IN subquery is defined with columns that are all non-nullable. The also ensures that any row with nulls returned by the subquery is not placed into the temporary table.
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. To run the test suite in a source directory, you must do make first. 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://kb.askmonty.org/v/reporting-bugs 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 socket=/tmp/mysql.sock 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 --database test --result-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. If you want to submit your test case you can send it to maria-developers@lists.launchpad.com or attach it to a bug report on https://bugs.launchpad.net/maria/. If the test case is really big or if it contains 'not public' data, then 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://ftp.askmonty.org/private and send a mail to https://bugs.launchpad.net/maria/ about it.