7ae21b18a6
log_t::FORMAT_10_5: physical redo log format tag log_phys_t: Buffered records in the physical format. The log record bytes will follow the last data field, making use of alignment padding that would otherwise be wasted. If there are multiple records for the same page, also those may be appended to an existing log_phys_t object if the memory is available. In the physical format, the first byte of a record identifies the record and its length (up to 15 bytes). For longer records, the immediately following bytes will encode the remaining length in a variable-length encoding. Usually, a variable-length-encoded page identifier will follow, followed by optional payload, whose length is included in the initially encoded total record length. When a mini-transaction is updating multiple fields in a page, it can avoid repeating the tablespace identifier and page number by setting the same_page flag (most significant bit) in the first byte of the log record. The byte offset of the record will be relative to where the previous record for that page ended. Until MDEV-14425 introduces a separate file-level log for redo log checkpoints and file operations, we will write the file-level records in the page-level redo log file. The record FILE_CHECKPOINT (which replaces MLOG_CHECKPOINT) will be removed in MDEV-14425, and one sequential scan of the page recovery log will suffice. Compared to MLOG_FILE_CREATE2, FILE_CREATE will not include any flags. If the information is needed, it can be parsed from WRITE records that modify FSP_SPACE_FLAGS. MLOG_ZIP_WRITE_STRING: Remove. The record was only introduced temporarily as part of this work, before being replaced with WRITE (along with MLOG_WRITE_STRING, MLOG_1BYTE, MLOG_nBYTES). mtr_buf_t::empty(): Check if the buffer is empty. mtr_t::m_n_log_recs: Remove. It suffices to check if m_log is empty. mtr_t::m_last, mtr_t::m_last_offset: End of the latest m_log record, for the same_page encoding. page_recv_t::last_offset: Reflects mtr_t::m_last_offset. Valid values for last_offset during recovery should be 0 or above 8. (The first 8 bytes of a page are the checksum and the page number, and neither are ever updated directly by log records.) Internally, the special value 1 indicates that the same_page form will not be allowed for the subsequent record. mtr_t::page_create(): Take the block descriptor as parameter, so that it can be compared to mtr_t::m_last. The INIT_INDEX_PAGE record will always followed by a subtype byte, because same_page records must be longer than 1 byte. trx_undo_page_init(): Combine the writes in WRITE record. trx_undo_header_create(): Write 4 bytes using a special MEMSET record that includes 1 bytes of length and 2 bytes of payload. flst_write_addr(): Define as a static function. Combine the writes. flst_zero_both(): Replaces two flst_zero_addr() calls. flst_init(): Do not inline the function. fsp_free_seg_inode(): Zerofill the whole inode. fsp_apply_init_file_page(): Initialize FIL_PAGE_PREV,FIL_PAGE_NEXT to FIL_NULL when using the physical format. btr_create(): Assert !page_has_siblings() because fsp_apply_init_file_page() must have been invoked. fil_ibd_create(): Do not write FILE_MODIFY after FILE_CREATE. fil_names_dirty_and_write(): Remove the parameter mtr. Write the records using a separate mini-transaction object, because any FILE_ records must be at the start of a mini-transaction log. recv_recover_page(): Add a fil_space_t* parameter. After applying log to the a ROW_FORMAT=COMPRESSED page, invoke buf_zip_decompress() to restore the uncompressed page. buf_page_io_complete(): Remove the temporary hack to discard the uncompressed page of a ROW_FORMAT=COMPRESSED page. page_zip_write_header(): Remove. Use mtr_t::write() or mtr_t::memset() instead, and update the compressed page frame separately. trx_undo_header_add_space_for_xid(): Remove. trx_undo_seg_create(): Perform the changes that were previously made by trx_undo_header_add_space_for_xid(). btr_reset_instant(): New function: Reset the table to MariaDB 10.2 or 10.3 format when rolling back an instant ALTER TABLE operation. page_rec_find_owner_rec(): Merge with the only callers. page_cur_insert_rec_low(): Combine writes by using a local buffer. MEMMOVE data from the preceding record whenever feasible (copying at least 3 bytes). page_cur_insert_rec_zip(): Combine writes to page header fields. PageBulk::insertPage(): Issue MEMMOVE records to copy a matching part from the preceding record. PageBulk::finishPage(): Combine the writes to the page header and to the sparse page directory slots. mtr_t::write(): Only log the least significant (last) bytes of multi-byte fields that actually differ. For updating FSP_SIZE, we must always write all 4 bytes to the redo log, so that the fil_space_set_recv_size() logic in recv_sys_t::parse() will work. mtr_t::memcpy(), mtr_t::zmemcpy(): Take a pointer argument instead of a numeric offset to the page frame. Only log the last bytes of multi-byte fields that actually differ. In fil_space_crypt_t::write_page0(), we must log also any unchanged bytes, so that recovery will recognize the record and invoke fil_crypt_parse(). Future work: MDEV-21724 Optimize page_cur_insert_rec_low() redo logging MDEV-21725 Optimize btr_page_reorganize_low() redo logging MDEV-21727 Optimize redo logging for ROW_FORMAT=COMPRESSED |
||
|---|---|---|
| BUILD | ||
| client | ||
| cmake | ||
| dbug | ||
| debian | ||
| Docs | ||
| extra | ||
| include | ||
| libmariadb@8e9c311610 | ||
| 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@a17b65a25f | ||
| zlib | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .travis.compiler.sh | ||
| .travis.yml | ||
| appveyor.yml | ||
| BUILD-CMAKE | ||
| CMakeLists.txt | ||
| config.h.cmake | ||
| configure.cmake | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| CREDITS | ||
| EXCEPTIONS-CLIENT | ||
| INSTALL-SOURCE | ||
| INSTALL-WIN-SOURCE | ||
| KNOWN_BUGS.txt | ||
| README.md | ||
| THIRDPARTY | ||
| VERSION | ||
Code status:
travis-ci.org (10.5 branch)ci.appveyor.com
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 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/library/new-and-old-releases/
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.
Live QA for beginner contributors
MariaDB has a dedicated time each week when we answer new contributor questions live on Zulip and IRC. From 8:00 to 10:00 UTC on Mondays, and 10:00 to 12:00 UTC on Thursdays, anyone can ask any questions they’d like, and a live developer will be available to assist.
New contributors can ask questions any time, but we will provide immediate feedback during that interval.
Licensing
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 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/
Bugs in the MySQL code can also be submitted at: https://bugs.mysql.com
The code for MariaDB, including all revision history, can be found at: https://github.com/MariaDB/server