![]() This split from MDEV-32294, discovered when inspecting how Item_subselect::used_tables_cache gets recalculated during 1st and 2nd executions of prepared statements. We build a list of outer references resolved against each select_lex. This list is not reset at the end of a prepared statement, so each element in this must be allocated on statement memory. Because of this we rely on MDEV-30073, as prior to this patch, some outer references are freed at the end of prepared statement execution. We use this list to recalculate Item_subselect::used_tables_cache There are a number of additional processing steps that need to happen during query merges. A derived table merge will leave a mix of SELECT_LEX::nest_base_level pointers in our query structure. Some Item::*processors will search for items that 'belong' only to the 'unit' being searched. We need to update this and nest_level when merging. We update SELECT_LEX::outer_references_resolved_here, in case an Item in a subquery is no longer an outer reference. We introduce a number tests in main.outer_reference, along with a way of wrapping each select to be executed in a number of different ways. TODO, check that the result of each of these different ways of execution is identical. We could wrap this into client/mysqltest and perhaps allow stacking of each execution method, such as --view (to create a view from our test statement and then select from the view) and --ps (to prepare our test statement, now selecting from a view, and compare data output from first and second executions). Name resolution fixes related to prepared statement execution. We no longer call fix_outer_field after the first execution, we now rely on the attribute depended_from, populated during the first execution. Code is added to Item_field::fix_fields to compensate. We allocate view field substituions on statement memory. When run as a prepared statement, this happens during the first execution. table_map fixes related to prepared statement and view processing. In setup_fields, during the 2nd execution of a prepared statement, we can call used_tables() prior to any caches being set up. This can result in incorrect processing. We also ban execution of EXPLAIN EXTENDED statements during mtr ps protocol runs as the generation of warnings varies due to the fact that some Item select_transformers cannot be run during execution of the prepare statement, so we would normally expect a different warning output. |
||
---|---|---|
.github | ||
BUILD | ||
client | ||
cmake | ||
dbug | ||
debian | ||
Docs | ||
extra | ||
include | ||
libmariadb@55abb32038 | ||
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