9c8bdc6c15
Let us use implement a simple fixed-size allocator for the adaptive hash index, insted of complicating mem_heap_t or mem_block_info_t. MEM_HEAP_BTR_SEARCH: Remove. mem_block_info_t::free_block(), mem_heap_free_block_free(): Remove. mem_heap_free_top(), mem_heap_get_top(): Remove. btr_sea::partition::spare: Replaces mem_block_info_t::free_block. This keeps one spare block per adaptive hash index partition, to process an insert. We must not wait for buf_pool.mutex while holding any btr_sea::partition::latch. That is why we cache one block for future allocations. This is protected by a new btr_sea::partition::blocks_mutex in order to relieve pressure on btr_sea::partition::latch. btr_sea::partition::prepare_insert(): Replaces btr_search_check_free_space_in_heap(). btr_sea::partition::erase(): Replaces ha_search_and_delete_if_found(). btr_sea::partition::cleanup_after_erase(): Replaces the most part of ha_delete_hash_node(). Unlike the previous implementation, we will retain a spare block for prepare_insert(). This should reduce some contention on buf_pool.mutex. btr_search.n_parts: Replaces btr_ahi_parts. btr_search.enabled: Replaces btr_search_enabled. This must hold whenever buf_block_t::index is set while a thread is holding a btr_sea::partition::latch. dict_index_t::search_info: Remove pointer indirection, and use Atomic_relaxed or Atomic_counter for most fields. btr_search_guess_on_hash(): Let the caller ensure that latch_mode is BTR_MODIFY_LEAF or BTR_SEARCH_LEAF. Release btr_sea::partition::latch before buffer-fixing the block. The page latch that we already acquired is preventing buffer pool eviction. We must validate both block->index and block->page.state while holding part.latch in order to avoid race conditions with buffer page relocation or buf_pool_t::resize(). btr_search_check_guess(): Remove the constant parameter can_only_compare_to_cursor_rec=false. ahi_node: Replaces ha_node_t. This has been tested by running the regression test suite with the adaptive hash index enabled: ./mtr --mysqld=--loose-innodb-adaptive-hash-index=ON Reviewed by: Vladislav Lesin |
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| include | ||
| libmariadb@52d0a38ed1 | ||
| libmysqld | ||
| libservices | ||
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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 our security-policy.
The code for MariaDB, including all revision history, can be found at: https://github.com/MariaDB/server