In preparation for the 2017-2 MariaDB Developer Unconference in Shenzhen https://mariadb.org/2017-2-developers-unconference-and-related-events-shenzh... next week, I cloned the https://github.com/alibaba/AliSQL repository and reviewed the changes to storage/innobase. The repository is based on commit c3a8ca1ed0063d4bca761ac9b57718796242ccc1 (tag: mysql-5.6.32) in the https://github.com/mysql/mysql-server/ repository. I read the 13,587 lines of diff generated by the following command: git diff c3a8ca1ed0063d4bca761ac9b57718796242ccc1 storage/innobase Features that already exist in MariaDB in some form: * Split the btr_search_latch (already present in MySQL 5.7/MariaDB 10.2.2) * Buffer pool "hazard pointer" (5.7/10.2.2) * Faster read view creation (done differently in WL#6578 MySQL 5.7/MariaDB 10.2.2) * Persistent auto_increment (done differently in MDEV-6076 in MariaDB 10.2.4) * Instant ADD COLUMN (done differently in MDEV-11369 in MariaDB 10.3.2) * Sequence engine (done differently in MDEV-10139 in MariaDB 10.3.1) New features: * Counters for buffer pool LRU eviction: MONITOR_LRU_BATCH are split into MONITOR_LRU_BATCH_FLUSH and MONITOR_LRU_BATCH_EVICT (Sounds like a good idea to me; maybe MariaDB should export these via status variables.) * Issue#24 SPLIT LOG BUFFER TO ROTATE LOG WRITE (I’d go further and change the LSN to count mtr_t::commit() instead of bytes, and to use a global buffer for mtr_t::log. This would require a new redo log format.) * Issue#31 OPTIMIZE CHECK/GRANT OF INNODB TABLE LOCK (I’d rather replace InnoDB table locks and dict_operation_lock with MDL.) * Issue#29: ADD INFORMATION_SCHEMA.INNODB_RSEG TABLE (I’d rather split the undo log into tablename.ibu files, also to ease import/export/backup.) * Issue#9: PROVIDE ADAPTIVE ALGORITHM FOR INNODB CONCURRENCY TICKETS (I think that the whole ticket business should be moved to the thread pool plugin.) * Issue#34: Support force drop table (I’d rather remove the InnoDB dictionary and have transactional .frm files, instead of writing work-arounds.) Best regards, Marko -- Marko Mäkelä, Lead Developer InnoDB MariaDB Corporation