MySQL 5.7 Release Notes - Download - MySQL

MySQL 5.7 Release Notes• On Mac OS X, preloading of client plugins specified with the LIBMYSQL_PLUGINS environmentvariable could fail unless the plugins were located in the hardwired default plugin directory. The CAPI now checks during plugin preloading for a LIBMYSQL_PLUGIN_DIR environment variable whichcan be set to the path name of the directory in which to look for client plugins. (Bug #13994567, Bug#18110355)• For utf8 and utf8mb4 strings, handler functions unnecessarily called a Unicode conversionfunction. (Bug #14057034)• Certain (... NULL ...) IN (...) expressions returned NULL when they should return 0, suchas SELECT (NULL, 1) IN ((0, 0), (0, 0)). (Bug #13944462)• Several -W warning flags were turned off for compilation in maintainer mode if MySQL wasconfigured with -DWITH_INNODB_MEMCACHED=1. (Bug #13898319)• The optimizer set up for dynamic range access in some cases where range access cannot be used,resulting in fallback to a table scan. (Bug #13814468)• Executing mysqladmin shutdown for a server running with the thread pool plugin enabled andservicing a large number of concurrent connections caused the server to exit abnormally. (Bug#13788920)• Calling the ExtractValue() function with an invalid XPath expression could in some cases lead toa failure of the server. (Bug #12428404, Bug #61065)• Use of a nonmulti-byte algorithm for skipping leading spaces in multi-byte strings could cause aserver exit. (Bug #12368495, Bug #18315770)• With ONLY_FULL_GROUP_BY SQL mode enabled, a query that uses GROUP BY on a column derivedfrom a subquery in the FROM clause failed with a column isn't in GROUP BY error, if the querywas in a view. (Bug #11923239)• For the utf8_bin collation, ORDER BY LOWER(col_name) could produce incorrect ordering. (Bug#69005, Bug #16691598)• Several issues identified by the Coverity static analysis tool were fixed. Thanks to Honza Horak forthe patch. (Bug #70830, Bug #17760511)• On Windows, the --local-service server option did not work, and was not displayed in the --help message. (Bug #69637, Bug #17049656)• The server wrote an excessive number of “Sort aborted” messages to the error log. (Bug #70173,Bug #17372396)• It was not possible to query a view with an ORDER BY clause that referenced an alias in the SELECTclause of the view definition, unless all columns in the view were named in the select list.To handle this problem, the server now writes a view differently into the .frm file that stores the viewdefinition. If you experience view-evaluation errors such as just described, drop and recreate theview so that the .frm file contains the updated view representation. (Bug #69678, Bug #17077305)• Overhead was reduced within critical sections of the my_fopen() and my_register_filename()mysys functions. Thanks to Po-Chun Chang for the patch. (Bug #70848)• The prototype of the Performance Schema instrumentation API mysql_cond_timedwait()call was fixed to be drop-in compatible with pthread_cond_timedwait(). This fix affects onlyimplementers of third-party plugins. (Bug #70628, Bug #17702677)• For debug builds, JSON-format EXPLAIN statements for queries that involve semi-joinmaterialization could cause a server exit. (Bug #70014, Bug #17305943)• For an existing user, GRANT with an empty password (IDENTIFIED BY [PASSWORD] '') did notchange the password. (Bug #69899, Bug #17256161)35