MySQL 5.7 Release Notes - Download - MySQL

MySQL 5.7 Release Notes• InnoDB: row_scan_index_for_mysql would allocate a buffer size of UNIV_PAGE_SIZE forrow_search_for_mysql. When the record length was greater than UNIV_PAGE_SIZE, a Valgrinderror would occur. (Bug #17378106)• InnoDB: During parallel full-text search (FTS) index creation, a scanner thread reads in documentsand passes them to the tokenizer. The tokenizer frees documents from memory when tokenizationis complete. When tokenizing documents with a large amount of text, the tokenizer thread wouldnot keep pace with the scanner thread. As a result, memory would not be freed fast enough and the“tokenization pending list” would grow in size. (Bug #17384979)• InnoDB: A full-text search (FTS) BOOLEAN MODE query with an invalid character in the query stringcould result in a memory access violation failure. (Bug #17350055)• InnoDB: trx_create and trx_free would be called for every memcached get request. (Bug#17371537, Bug #70172)• InnoDB: When innodb_file_per_table is set to OFF, replication would fail with error code 1880when truncating tables. For tables that reside in the shared tablespace, the truncate log file nameused during the truncate action was not unique. The error is due to a MySQL 5.7.2 code regressionrelated to Bug #14174004. (Bug #17327409)• InnoDB: trx_sys_t::ro_trx_list has been removed. Adding and removing transactionsfrom the ro_trx_list can be costly, and placing transactions on the list by default is no longernecessary after mutex related optimizations implemented in MySQL 5.7.2. User transactions are stillplaced on the trx_t::mysql_trx_list. Currently, background read-only transactions are notplaced on any list. (Bug #17332300)• InnoDB: When InnoDB is retrieving rows and a KILL QUERY statement is issued, InnoDB wouldreturn false errors. (Bug #16950658)• InnoDB: The hardcoded size for the srv_max_n_threads variable was insufficient. The variablesetting is now configured based on the maximum number of connection threads and InnoDBbackground threads. (Bug #16884077)• InnoDB: In btr_validate_level there are checks to ensure that all B-tree pages are markedwhen allocated. The checks would fail on the change buffer because the allocation of change bufferpages is handled differently than other B-tree pages. (Bug #16884217)• InnoDB: InnoDB would set UNIV_WORD_SIZE to 4 for both Windows 32-bit and 64-bit systems.With this patch, UNIV_WORD_SIZE is set to 8 on 64-bit Windows systems. This patch also removesUNIV_WORD_ALIGNMENT, which is no longer used. (Bug #16774645)• InnoDB: When the change buffer is enabled, InnoDB would fail to write a transaction log recordwhen merging a record from the insert buffer to a secondary index page if the insert was performedas an “update-in-place”. (Bug #16752251, Bug #69122)• InnoDB: A SELECT COUNT(*) query would take a long time to complete when run concurrentlywith a LOAD DATA operation. The mtr_memo_contains function, which determines if an object ispart of a memo in a mini transaction, contained a nested loop that caused the query to run slowly.(Bug #16764240, Bug #69141)• InnoDB: Due to a regression in MySQL 5.6, creating or dropping tables withinnodb_force_recovery set to 3 (SRV_FORCE_NO_TRX_UNDO) would fail. Additionally, this bugfix includes a code modification that sets InnoDB to read-only when innodb_force_recovery isset to a value greater than 3 (SRV_FORCE_NO_TRX_UNDO). (Bug #16631778, Bug #69892)• InnoDB: An InnoDB memcached configuration error message contained an incorrect file name.The error message stated, Please create config table containers in databaseinnodb_memcache by running innodb_config.sql. error 31. The correct file nameis innodb_memcached_config.sql. Also, the “error 31” portion of the error message has beentranslated to its text equivalent, which is “Table not found”. (Bug #16498810, Bug #68684)47