0906dc49e8
Here's what started happening after the patch that fixed the bug mdev-10454 with query reported for the bug SELECT * FROM t t1 right JOIN t t2 ON (t2.pk = t1.pk) WHERE (t2.i, t2.pk) NOT IN ( SELECT t3.i, t3.i FROM t t3, t t4 ) AND t1.c = 'foo'; The patch added an implementation of propagate_equal_fields() for the class Item_row and thus opened the possibility of equal fields substitutions. At the prepare stage after setup_conds() called for WHERE condition had completed the flag of maybe_null of the Item_row object created for (t2.i, t2.pk) was set to false, because the maybe_null flags of both elements were set to false. However the flag of maybe_null for t1.pk from the ON condition were set to true, because t1 was an inner table of an outer join. At the optimization stage the outer join was converted to inner join, but the maybe_null flags were not corrected and remained the same. So after the substitution t2.pk/t1.pk. the maybe_null flag for the row remained false while the maybe_flag for the second element of the row was true. As a result, when the in-to_exists transformation was performed for the NOT IN predicate the guards variables were not created for the elements of the row, but a guard object for the second element was created. The object were not valid because it referred to NULL as a guard variable. This ultimately caused a crash when the expression with the guard was evaluated at the execution stage. The patch made sure that the guard objects are not created without guard variables. Yet it does not resolve the problem of inconsistent maybe_null flags. and it might be that the problem will pop op in other pieces of code. The resolution of this problem is not easy, but the problem should be resolved in future versions. |
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BUILD | ||
client | ||
cmake | ||
dbug | ||
debian | ||
Docs | ||
extra | ||
include | ||
libmariadb@d138735629 | ||
libmysqld | ||
libservices | ||
man | ||
mysql-test | ||
mysys | ||
mysys_ssl | ||
pcre | ||
plugin | ||
randgen/conf | ||
scripts | ||
sql | ||
sql-bench | ||
sql-common | ||
storage | ||
strings | ||
support-files | ||
tests | ||
unittest | ||
vio | ||
win | ||
wsrep | ||
zlib | ||
.gitattributes | ||
.gitignore | ||
.gitmodules | ||
.travis.compiler.sh | ||
.travis.yml | ||
BUILD-CMAKE | ||
CMakeLists.txt | ||
config.h.cmake | ||
configure.cmake | ||
COPYING | ||
COPYING.thirdparty | ||
CREDITS | ||
EXCEPTIONS-CLIENT | ||
INSTALL-SOURCE | ||
INSTALL-WIN-SOURCE | ||
KNOWN_BUGS.txt | ||
README.md | ||
VERSION |
MariaDB: drop-in replacement for MySQL
MariaDB is 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. 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 Foundation and the MariaDB Corporation, 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: http://mariadb.org/ https://mariadb.com/kb/en/ https://mariadb.com/kb/en/mariadb-vs-mysql-features/ https://mariadb.com/kb/en/mariadb-versus-mysql-features/ https://mariadb.com/kb/en/mariadb-versus-mysql-compatibility/
As MariaDB is a full replacement of MySQL, the MySQL manual at http://dev.mysql.com/doc is generally applicable.
Help:
More help is available from the Maria Discuss mailing list https://launchpad.net/~maria-discuss and the #maria IRC channel on Freenode.
License:
NOTE:
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, COPYING.LESSER, and COPYING.thirdparty files.
Bug Reports:
Bug and/or error reports regarding MariaDB should be submitted at http://mariadb.org/jira
Bugs in the MySQL code can also be submitted at http://bugs.mysql.com
The code for MariaDB, including all revision history, can be found at: https://github.com/MariaDB/server