d7b2102fdc
This commit updates default memory allocations size used with MEM_ROOT objects to minumize the number of calls to malloc(). Changes: - Updated MEM_ROOT block sizes in sql_const.h - Updated MALLOC_OVERHEAD to also take into account the extra memory allocated by my_malloc() - Updated init_alloc_root() to only take MALLOC_OVERHEAD into acount as buffer size, not MALLOC_OVERHEAD + sizeof(USED_MEM). - Reset mem_root->first_block_usage if and only if first block was used. - Increase MEM_ROOT buffers sized used by my_load_defaults, plugin_init, Create_tmp_table, allocate_table_share, TABLE and TABLE_SHARE. This decreases number of malloc calls during queries. - Use a small buffer for THD->main_mem_root in THD::THD. This avoids multiple malloc() call for new connections. I tried the above changes on a complex select query with 12 tables. The following shows the number of extra allocations that where used to increase the size of the MEM_ROOT buffers. Original code: - Connection to MariaDB: 9 allocations - First query run: 146 allocations - Second query run: 24 allocations Max memory allocated for thd when using with heap table: 61,262,408 Max memory allocated for thd when using Aria tmp table: 419,464 After changes: Connection to MariaDB: 0 allocations - First run: 25 allocations - Second run: 7 allocations Max memory allocated for thd when using with heap table: 61,347,424 Max memory allocated for thd when using Aria table: 529,168 The new code uses slighly more memory, but avoids memory fragmentation and is slighly faster thanks to much fewer calls to malloc(). |
||
|---|---|---|
| .github | ||
| BUILD | ||
| client | ||
| cmake | ||
| dbug | ||
| debian | ||
| Docs | ||
| extra | ||
| include | ||
| libmariadb@3f2196d84e | ||
| 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@1c61b809d1 | ||
| 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:
ci.appveyor.com
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