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Rex 7d46ee3336 MDEV-35673 Item_subselect::used_tables_cache issues with outer references and optimization.
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.
2025-06-05 18:11:31 +11:00
.github Merge 10.6 into 10.9 2023-05-19 15:11:06 +03:00
BUILD Merge branch '10.6' into 10.11 2024-04-26 08:02:49 +02:00
client MDEV-35673 Item_subselect::used_tables_cache issues with outer references and optimization. 2025-06-05 18:11:31 +11:00
cmake Replace deprecated CMAKE_COMPILER_IS_GNU(CC|CXX) with CMAKE_(C|CXX)_COMPILER_ID 2025-06-03 18:16:35 +10:00
dbug Merge 10.6 into 10.8 2023-02-10 13:43:53 +02:00
debian Merge branch '10.6' into 10.11 2025-01-30 11:55:13 +01:00
Docs Merge 10.4 into 10.5 2022-09-26 13:34:38 +03:00
extra Merge branch '10.6' into 10.11 2025-05-26 16:59:32 +02:00
include Merge branch '10.11' into 10.11 2025-05-21 14:43:57 +02:00
libmariadb@55abb32038 new CC 2025-04-20 20:48:21 +02:00
libmysqld Merge branch '10.6' into 10.11 2025-01-30 11:55:13 +01:00
libservices Merge 10.6 into 10.11 2024-02-08 15:04:46 +02:00
man Merge branch '10.6' into 10.11 2024-07-22 15:14:50 +02:00
mysql-test MDEV-35673 Item_subselect::used_tables_cache issues with outer references and optimization. 2025-06-05 18:11:31 +11:00
mysys Replace deprecated CMAKE_COMPILER_IS_GNU(CC|CXX) with CMAKE_(C|CXX)_COMPILER_ID 2025-06-03 18:16:35 +10:00
mysys_ssl MDEV-35838 libressl support differences in CRYPTO_set_mem_functions 2025-01-14 12:13:22 +11:00
plugin Merge 10.6 into 10.11 2025-05-26 08:10:47 +03:00
randgen/conf Group commit for maria engine. 2010-02-12 15:12:28 +02:00
scripts Replace deprecated CMAKE_COMPILER_IS_GNU(CC|CXX) with CMAKE_(C|CXX)_COMPILER_ID 2025-06-03 18:16:35 +10:00
sql MDEV-35673 Item_subselect::used_tables_cache issues with outer references and optimization. 2025-06-05 18:11:31 +11:00
sql-bench Updated sql-bench to run with PostgreSQL 14.9 2023-09-09 15:14:45 +03:00
sql-common Merge branch '10.6' into 10.11 2025-01-30 11:55:13 +01:00
storage Replace deprecated CMAKE_COMPILER_IS_GNU(CC|CXX) with CMAKE_(C|CXX)_COMPILER_ID 2025-06-03 18:16:35 +10:00
strings Merge branch '10.6' into 10.11 2025-05-26 16:59:32 +02:00
support-files Merge branch '10.6' into 10.11 2025-04-26 10:47:03 +02:00
tests Merge branch '10.6' into 10.11 2025-04-26 10:47:03 +02:00
tpool Merge branch '10.6' into 10.11 2025-04-21 11:23:11 +02:00
unittest Merge 10.6 into 10.11 2024-12-19 15:38:53 +02:00
vio Merge branch '10.6' into 10.11 2025-05-26 16:59:32 +02:00
win Cleanup CMake code (Windows-specific) 2025-04-04 08:58:40 +02:00
wsrep-lib@e55f01ce1e MDEV-36422 Build fails with cmake 4.0.0 due to wsrep 2025-04-10 13:05:19 +02:00
zlib Merge branch 'merge-zlib' (1.3.1) into 10.4 2024-04-26 13:50:03 +02:00
.clang-format Remove duplicate key "Language" from .clang-format 2024-04-17 16:52:37 +02:00
.gitattributes Merge branch '10.5' into 10.6 2022-02-03 17:01:31 +01:00
.gitignore Merge 10.6 into 10.11 2025-05-21 07:36:35 +03:00
.gitlab-ci.yml Merge branch '10.6' into 10.11 2024-07-22 15:14:50 +02:00
.gitmodules Merge remote-tracking branch '10.4' into 10.5 2023-03-31 21:32:41 +02:00
appveyor.yml Fix appveyor config 2025-04-18 19:53:55 +02:00
BUILD-CMAKE Minor spelling fixes in code comments, docs and output 2018-01-12 16:49:02 +02:00
CMakeLists.txt Replace deprecated CMAKE_COMPILER_IS_GNU(CC|CXX) with CMAKE_(C|CXX)_COMPILER_ID 2025-06-03 18:16:35 +10:00
config.h.cmake Cleanup CMake code (Windows-specific) 2025-04-04 08:58:40 +02:00
configure.cmake Merge branch '10.6' into 10.11 2024-10-29 15:24:38 +01:00
CONTRIBUTING.md Remove mention of Freenode 2021-09-22 07:15:08 +02:00
COPYING Update FSF Address 2019-05-11 21:29:06 +03:00
CREDITS Update sponsors 2024-08-12 09:32:30 +01:00
INSTALL-SOURCE Update AskMonty and Atlassian references to MariaDB 2016-03-08 15:24:01 +02:00
INSTALL-WIN-SOURCE Update AskMonty and Atlassian references to MariaDB 2016-03-08 15:24:01 +02:00
KNOWN_BUGS.txt Changed some MySQL names in messages to MariaDB 2018-12-09 20:49:05 +02:00
README.md Update README for branch choice 2024-05-29 13:49:32 +01:00
THIRDPARTY Merge branch '10.6' into 10.11 2024-02-01 18:36:14 +01:00
VERSION bump the VERSION 2025-05-22 10:23:36 -04:00

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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.org

https://mariadb.com/kb/en/

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.

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