![]() Queries having the following form may cause a crash SELECT t1.a FROM ( SELECT a AS a1 FROM t1 ) dt JOIN t1 ON a1 LIKE EXISTS ( SELECT a + RAND () FROM t1 UNION SELECT a FROM t1); because the table t1 has some JOIN cleanup operations performed prematurely during the subselect. In this particular case, the presence of RAND() makes the subquery uncacheable, necessitating the need to execute the subquery multiple times during join record evaluation. Each time the subquery runs, it creates its own JOIN structure which has references to the table t1. When the subquery completes, JOIN::cleanup and functions called by it result in ha_end_keyread() being called on table t1. However, we are not done with table t1 because the upper level `select t1.a from...` query requires table t1 to be open. To solve this, we make the executor aware of when we're in subqueries like this and delay JOIN cleanup until the end of the query. |
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BUILD | ||
client | ||
cmake | ||
dbug | ||
debian | ||
Docs | ||
extra | ||
include | ||
libmariadb@867f0d1825 | ||
libmysqld | ||
libservices | ||
man | ||
mysql-test | ||
mysys | ||
mysys_ssl | ||
plugin | ||
randgen/conf | ||
scripts | ||
sql | ||
sql-bench | ||
sql-common | ||
storage | ||
strings | ||
support-files | ||
tests | ||
tpool | ||
unittest | ||
vio | ||
win | ||
wsrep-lib@e55f01ce1e | ||
zlib | ||
.clang-format | ||
.gitattributes | ||
.gitignore | ||
.gitlab-ci.yml | ||
.gitmodules | ||
appveyor.yml | ||
BUILD-CMAKE | ||
CMakeLists.txt | ||
config.h.cmake | ||
configure.cmake | ||
CONTRIBUTING.md | ||
COPYING | ||
CREDITS | ||
INSTALL-SOURCE | ||
INSTALL-WIN-SOURCE | ||
KNOWN_BUGS.txt | ||
README.md | ||
THIRDPARTY | ||
VERSION |
Code status:
MariaDB: The innovative open source database
MariaDB was designed as a drop-in replacement of MySQL(R) with more features, new storage engines, fewer bugs, and better performance.
MariaDB is brought to you by the MariaDB Foundation and the MariaDB Corporation. Please read the CREDITS file for details about the MariaDB Foundation, and who is developing MariaDB.
MariaDB is developed by many of the original developers of MySQL who now work for the MariaDB Corporation, the MariaDB Foundation and by many people in the community.
MySQL, which is the base of MariaDB, is a product and trademark of Oracle Corporation, Inc. For a list of developers and other contributors, see the Credits appendix. You can also run 'SHOW authors' to get a list of active contributors.
A description of the MariaDB project and a manual can be found at:
https://mariadb.com/kb/en/mariadb-vs-mysql-features/
https://mariadb.com/kb/en/mariadb-versus-mysql-compatibility/
https://mariadb.com/kb/en/new-and-old-releases/
Getting the code, building it and testing it
Refer to the following guide: https://mariadb.org/get-involved/getting-started-for-developers/get-code-build-test/ which outlines how to build the source code correctly and run the MariaDB testing framework, as well as which branch to target for your contributions.
Help
More help is available from the Maria Discuss mailing list https://lists.mariadb.org/postorius/lists/discuss.lists.mariadb.org/ and MariaDB's Zulip instance, https://mariadb.zulipchat.com/
Licensing
MariaDB is specifically available only under version 2 of the GNU General Public License (GPLv2). (I.e. Without the "any later version" clause.) This is inherited from MySQL. Please see the README file in the MySQL distribution for more information.
License information can be found in the COPYING file. Third party license information can be found in the THIRDPARTY file.
Bug Reports
Bug and/or error reports regarding MariaDB should be submitted at: https://jira.mariadb.org
For reporting security vulnerabilities see: https://mariadb.org/about/security-policy/
The code for MariaDB, including all revision history, can be found at: https://github.com/MariaDB/server