mirror of
https://github.com/MariaDB/server.git
synced 2025-01-16 03:52:35 +01:00
MariaDB server is a community developed fork of MySQL server. Started by core members of the original MySQL team, MariaDB actively works with outside developers to deliver the most featureful, stable, and sanely licensed open SQL server in the industry.
amazon-web-servicesdatabasefulltext-searchgalerageographical-information-systeminnodbjsonmariadbmysqlrdbmsrelational-databasessqlstorage-enginevector-database
8ade414b28
Problem: If there is a predicate on a column referenced by MIN/MAX and that predicate is not present in all the disjunctions on keyparts earlier in the compound index, Loose Index Scan will not return correct result. Analysis: When loose index scan is chosen, range optimizer currently groups all the predicates that contain group parts separately and minmax parts separately. It therefore applies all the conditions on the group parts first to the fetched row. Then in the call to next_max, it processes the conditions which have min/max keypart. For ex in the following query: Select f1, max(f2) from t1 where (f1 = 10 and f2 = 13) or (f1 = 3) group by f1; Condition (f2 = 13) would be applied even for rows that satisfy (f1 = 3) thereby giving wrong results. Solution: Do not choose loose_index_scan for such cases. So a new rule WA2 is introduced to take care of the same. WA2: "If there are predicates on C, these predicates must be in conjuction to all predicates on all earlier keyparts in I." Todo the same, fix reuses the function get_constant_key_infix(). Since this funciton will fail for all multi-range conditions, it is re-written to recognize that if the sub-conditions are equivalent across the disjuncts: it will now succeed. And to achieve this a new helper function is introduced called all_same(). The fix also moves the test of NGA3 up to the former only caller, get_constant_key_infix(). mysql-test/r/group_min_max_innodb.result: Added test result change for Bug#17909656 mysql-test/t/group_min_max_innodb.test: Added test cases for Bug#17909656 sql/opt_range.cc: Introduced Rule WA2 because of Bug#17909656 |
||
|---|---|---|
| .bzr-mysql | ||
| BUILD | ||
| client | ||
| cmake | ||
| cmd-line-utils | ||
| dbug | ||
| Docs | ||
| extra | ||
| include | ||
| libmysql | ||
| libmysqld | ||
| libservices | ||
| man | ||
| mysql-test | ||
| mysys | ||
| packaging | ||
| plugin | ||
| regex | ||
| scripts | ||
| sql | ||
| sql-bench | ||
| sql-common | ||
| storage | ||
| strings | ||
| support-files | ||
| tests | ||
| unittest | ||
| vio | ||
| win | ||
| zlib | ||
| .bzrignore | ||
| BUILD-CMAKE | ||
| CMakeLists.txt | ||
| config.h.cmake | ||
| configure.cmake | ||
| COPYING | ||
| INSTALL-SOURCE | ||
| INSTALL-WIN-SOURCE | ||
| README | ||
| VERSION | ||
MySQL Server 5.5 This is a release of MySQL, a dual-license SQL database server. For the avoidance of doubt, this particular copy of the software is released under the version 2 of the GNU General Public License. MySQL is brought to you by Oracle. Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. License information can be found in the COPYING file. MySQL FOSS License Exception We want free and open source software applications under certain licenses to be able to use specified GPL-licensed MySQL client libraries despite the fact that not all such FOSS licenses are compatible with version 2 of the GNU General Public License. Therefore there are special exceptions to the terms and conditions of the GPLv2 as applied to these client libraries, which are identified and described in more detail in the FOSS License Exception at <http://www.mysql.com/about/legal/licensing/foss-exception.html>. This distribution may include materials developed by third parties. For license and attribution notices for these materials, please refer to the documentation that accompanies this distribution (see the "Licenses for Third-Party Components" appendix) or view the online documentation at <http://dev.mysql.com/doc/>. GPLv2 Disclaimer For the avoidance of doubt, except that if any license choice other than GPL or LGPL is available it will apply instead, Oracle elects to use only the General Public License version 2 (GPLv2) at this time for any software where a choice of GPL license versions is made available with the language indicating that GPLv2 or any later version may be used, or where a choice of which version of the GPL is applied is otherwise unspecified. For further information about MySQL or additional documentation, see: - The latest information about MySQL: http://www.mysql.com - The current MySQL documentation: http://dev.mysql.com/doc Some Reference Manual sections of special interest: - If you are migrating from an older version of MySQL, please read the "Upgrading from..." section. - To see what MySQL can do, take a look at the features section. - For installation instructions, see the Installing and Upgrading chapter. - For the new features/bugfix history, see the MySQL Change History appendix. You can browse the MySQL Reference Manual online or download it in any of several formats at the URL given earlier in this file. Source distributions include a local copy of the manual in the Docs directory.